diff --git a/app/src/main/kotlin/org/db3/airmq/features/map/MapScreen.kt b/app/src/main/kotlin/org/db3/airmq/features/map/MapScreen.kt
index c22ec64..de01919 100644
--- a/app/src/main/kotlin/org/db3/airmq/features/map/MapScreen.kt
+++ b/app/src/main/kotlin/org/db3/airmq/features/map/MapScreen.kt
@@ -23,6 +23,7 @@ import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleEventObserver
 import androidx.lifecycle.compose.LocalLifecycleOwner
 import kotlinx.coroutines.flow.collectLatest
+import org.db3.airmq.R
 import org.db3.airmq.features.map.MapScreenContract.Action
 import org.db3.airmq.features.map.MapScreenContract.Event
 import org.db3.airmq.sdk.map.domain.MapItem
@@ -66,6 +67,13 @@ fun MapScreen(
         MapTopControls(
             selectedSensor = uiState.selectedTopSensor,
             onSensorSelected = { viewModel.onEvent(Event.TopSensorSelected(it)) },
+            onHelpClick = {
+                Toast.makeText(
+                    context,
+                    context.getString(R.string.map_sensor_help_title),
+                    Toast.LENGTH_SHORT
+                ).show()
+            },
             modifier = Modifier
                 .align(Alignment.TopEnd)
                 .padding(top = 20.dp, end = 16.dp)
diff --git a/app/src/main/kotlin/org/db3/airmq/features/map/MapUiComponents.kt b/app/src/main/kotlin/org/db3/airmq/features/map/MapUiComponents.kt
index f9d7aa2..188b605 100644
--- a/app/src/main/kotlin/org/db3/airmq/features/map/MapUiComponents.kt
+++ b/app/src/main/kotlin/org/db3/airmq/features/map/MapUiComponents.kt
@@ -7,26 +7,38 @@ import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.wrapContentHeight
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.FilterChip
+import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import org.db3.airmq.R
 import org.db3.airmq.features.common.AirMqButton
@@ -36,38 +48,168 @@ import org.db3.airmq.features.map.MapScreenContract.DeviceSensorType
 import org.db3.airmq.features.map.MapScreenContract.SearchResult
 import org.db3.airmq.features.map.MapScreenContract.SensorType
 import org.db3.airmq.features.map.MapScreenContract.TimeRange
+import org.db3.airmq.ui.theme.AirMQTheme
 
 @Composable
 fun MapTopControls(
     selectedSensor: SensorType,
     onSensorSelected: (SensorType) -> Unit,
+    onHelpClick: () -> Unit,
+    initiallyExpanded: Boolean = false,
     modifier: Modifier = Modifier
 ) {
-    Surface(
-        modifier = modifier,
-        shape = RoundedCornerShape(22.dp),
-        tonalElevation = 2.dp,
-        shadowElevation = 6.dp,
-        color = Color.White
+    var isExpanded by remember(initiallyExpanded) { mutableStateOf(initiallyExpanded) }
+    val arrowRotation = if (isExpanded) 180f else 0f
+    val selectedLabel = when (selectedSensor) {
+        SensorType.DUST -> stringResource(id = R.string.map_sensor_air_quality)
+        SensorType.RADIOACTIVITY -> stringResource(id = R.string.map_sensor_radioactivity)
+    }
+
+    Box(
+        modifier = modifier
+            .width(234.dp)
+            .wrapContentHeight()
     ) {
-        Row(
-            modifier = Modifier.padding(horizontal = 10.dp, vertical = 8.dp),
-            horizontalArrangement = Arrangement.spacedBy(8.dp)
+        Column(
+            modifier = Modifier
+                .align(Alignment.TopStart)
+                .padding(start = 10.dp, top = 10.dp, end = 10.dp)
         ) {
-            FilterChip(
-                selected = selectedSensor == SensorType.DUST,
-                onClick = { onSensorSelected(SensorType.DUST) },
-                label = { Text(stringResource(id = R.string.map_sensor_dust)) }
-            )
-            FilterChip(
-                selected = selectedSensor == SensorType.RADIOACTIVITY,
-                onClick = { onSensorSelected(SensorType.RADIOACTIVITY) },
-                label = { Text(stringResource(id = R.string.map_sensor_radioactivity)) }
+            Surface(
+                modifier = Modifier
+                    .width(214.dp)
+                    .height(36.dp)
+                    .clickable { isExpanded = !isExpanded },
+                shape = RoundedCornerShape(18.dp),
+                shadowElevation = 10.dp,
+                color = Color.White
+            ) {
+                Row(
+                    modifier = Modifier
+                        .fillMaxSize()
+                        .padding(start = 12.dp, end = 48.dp),
+                    verticalAlignment = Alignment.CenterVertically
+                ) {
+                    Icon(
+                        painter = painterResource(id = R.drawable.ic_arrow_down_dark),
+                        contentDescription = null,
+                        tint = Color(0x8A000000),
+                        modifier = Modifier.rotate(arrowRotation)
+                    )
+                    Spacer(modifier = Modifier.width(8.dp))
+                    Text(
+                        text = selectedLabel.uppercase(),
+                        style = MaterialTheme.typography.labelLarge,
+                        color = Color(0x61000000)
+                    )
+                }
+            }
+
+            if (isExpanded) {
+                Surface(
+                    modifier = Modifier
+                        .width(214.dp)
+                        .padding(top = 8.dp),
+                    shape = RoundedCornerShape(18.dp),
+                    shadowElevation = 10.dp,
+                    color = Color.White
+                ) {
+                    Column(modifier = Modifier.padding(top = 8.dp, bottom = 10.dp)) {
+                        SensorTypeItem(
+                            iconRes = R.drawable.ic_dust,
+                            titleRes = R.string.map_sensor_air_quality,
+                            selected = selectedSensor == SensorType.DUST,
+                            onClick = {
+                                onSensorSelected(SensorType.DUST)
+                                isExpanded = false
+                            }
+                        )
+                        HorizontalDivider(color = Color(0x1F000000))
+                        SensorTypeItem(
+                            iconRes = R.drawable.ic_radiation,
+                            titleRes = R.string.map_sensor_radioactivity,
+                            selected = selectedSensor == SensorType.RADIOACTIVITY,
+                            onClick = {
+                                onSensorSelected(SensorType.RADIOACTIVITY)
+                                isExpanded = false
+                            }
+                        )
+                        Text(
+                            text = stringResource(id = R.string.map_sensor_help_link),
+                            modifier = Modifier
+                                .align(Alignment.CenterHorizontally)
+                                .padding(top = 12.dp)
+                                .clickable {
+                                    onHelpClick()
+                                    isExpanded = false
+                                },
+                            style = MaterialTheme.typography.bodyMedium,
+                            color = Color(0x8A000000),
+                            textDecoration = TextDecoration.Underline
+                        )
+                    }
+                }
+            }
+        }
+
+        Box(
+            modifier = Modifier
+                .align(Alignment.TopEnd)
+                .size(56.dp)
+                .background(
+                    brush = Brush.linearGradient(
+                        colors = listOf(Color(0xFF00FF6D), Color(0xFF03AEF9))
+                    ),
+                    shape = CircleShape
+                ),
+            contentAlignment = Alignment.Center
+        ) {
+            Icon(
+                painter = painterResource(
+                    id = if (selectedSensor == SensorType.RADIOACTIVITY) {
+                        R.drawable.ic_radiation
+                    } else {
+                        R.drawable.ic_dust
+                    }
+                ),
+                contentDescription = null,
+                tint = Color.White,
+                modifier = Modifier.size(24.dp)
             )
         }
     }
 }
 
+@Composable
+private fun SensorTypeItem(
+    iconRes: Int,
+    titleRes: Int,
+    selected: Boolean,
+    onClick: () -> Unit
+) {
+    val textColor = if (selected) Color(0xFF1C1C1C) else Color(0xFF616161)
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clickable(onClick = onClick)
+            .padding(horizontal = 16.dp, vertical = 10.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Icon(
+            painter = painterResource(id = iconRes),
+            contentDescription = null,
+            tint = textColor,
+            modifier = Modifier.size(18.dp)
+        )
+        Spacer(modifier = Modifier.width(10.dp))
+        Text(
+            text = stringResource(id = titleRes),
+            style = MaterialTheme.typography.bodyMedium,
+            color = textColor
+        )
+    }
+}
+
 @Composable
 fun MapFloatingActions(
     onSearchClick: () -> Unit,
@@ -340,3 +482,118 @@ private fun DeviceSensorRow(
         )
     }
 }
+
+@Preview(showBackground = true)
+@Composable
+private fun PreviewMapTopControlsCollapsedDust() {
+    AirMQTheme {
+        MapTopControls(
+            selectedSensor = SensorType.DUST,
+            onSensorSelected = {},
+            onHelpClick = {}
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+private fun PreviewMapTopControlsExpandedDust() {
+    AirMQTheme {
+        MapTopControls(
+            selectedSensor = SensorType.DUST,
+            onSensorSelected = {},
+            onHelpClick = {},
+            initiallyExpanded = true
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+private fun PreviewMapTopControlsExpandedRadioactivity() {
+    AirMQTheme {
+        MapTopControls(
+            selectedSensor = SensorType.RADIOACTIVITY,
+            onSensorSelected = {},
+            onHelpClick = {},
+            initiallyExpanded = true
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+private fun PreviewMapSearchOverlayEmpty() {
+    AirMQTheme {
+        MapSearchOverlay(
+            query = "Minsk",
+            results = emptyList(),
+            onQueryChanged = {},
+            onClose = {},
+            onResultClick = {}
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+private fun PreviewMapSearchOverlayWithResults() {
+    AirMQTheme {
+        MapSearchOverlay(
+            query = "Minsk",
+            results = listOf(
+                SearchResult(id = "1", title = "AirMQ #42", subtitle = "Minsk"),
+                SearchResult(id = "2", title = "AirMQ #91", subtitle = "Salihorsk")
+            ),
+            onQueryChanged = {},
+            onClose = {},
+            onResultClick = {}
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+private fun PreviewMapDevicePanelDust() {
+    AirMQTheme {
+        MapDevicePanel(
+            data = DevicePanelState(
+                id = "42",
+                name = "AirMQ #42",
+                status = "Online",
+                selectedRange = TimeRange.DAY,
+                displayedDateRange = "Today",
+                selectedSensor = DeviceSensorType.DUST
+            ),
+            onClose = {},
+            onOpenDevice = {},
+            onRangeSelected = {},
+            onDateBack = {},
+            onDateForward = {},
+            onSensorSelected = {}
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+private fun PreviewMapDevicePanelRadioactivity() {
+    AirMQTheme {
+        MapDevicePanel(
+            data = DevicePanelState(
+                id = "43",
+                name = "AirMQ #43",
+                status = "Offline",
+                selectedRange = TimeRange.WEEK,
+                displayedDateRange = "Last 7 days",
+                selectedSensor = DeviceSensorType.RADIOACTIVITY
+            ),
+            onClose = {},
+            onOpenDevice = {},
+            onRangeSelected = {},
+            onDateBack = {},
+            onDateForward = {},
+            onSensorSelected = {}
+        )
+    }
+}
diff --git a/app/src/main/res/drawable/ic_arrow_down_dark.xml b/app/src/main/res/drawable/ic_arrow_down_dark.xml
new file mode 100644
index 0000000..985760f
--- /dev/null
+++ b/app/src/main/res/drawable/ic_arrow_down_dark.xml
@@ -0,0 +1,15 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillAlpha="0"
+        android:fillColor="#FF000000"
+        android:pathData="M0,0h24v24h-24z" />
+    <path
+        android:fillAlpha="0.54"
+        android:fillColor="#FF000000"
+        android:pathData="M8.54,11.38l2.72,2.72c0.41,0.41 1.07,0.41 1.48,0l2.72,-2.72c0.66,-0.66 0.19,-1.79 -0.74,-1.79l-5.44,0C8.34,9.59 7.88,10.72 8.54,11.38z"
+        android:strokeAlpha="0.54" />
+</vector>
diff --git a/app/src/main/res/drawable/ic_dust.xml b/app/src/main/res/drawable/ic_dust.xml
new file mode 100644
index 0000000..452b0f8
--- /dev/null
+++ b/app/src/main/res/drawable/ic_dust.xml
@@ -0,0 +1,42 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M15.62,11.36m-2.57,0a2.57,2.57 0,1 1,5.14 0a2.57,2.57 0,1 1,-5.14 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M10.16,17.59m-2.3,0a2.3,2.3 0,1 1,4.6 0a2.3,2.3 0,1 1,-4.6 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M6.09,7.24m-2.31,0a2.31,2.31 0,1 1,4.62 0a2.31,2.31 0,1 1,-4.62 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M21.35,10.63m-1.65,0a1.65,1.65 0,1 1,3.3 0a1.65,1.65 0,1 1,-3.3 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M5.76,13.19m-1.83,0a1.83,1.83 0,1 1,3.66 0a1.83,1.83 0,1 1,-3.66 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M11.78,6.51m-1.83,0a1.83,1.83 0,1 1,3.66 0a1.83,1.83 0,1 1,-3.66 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M4.08,18.66m-1.47,0a1.47,1.47 0,1 1,2.94 0a1.47,1.47 0,1 1,-2.94 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M22.08,16.1m-0.72,0a0.72,0.72 0,1 1,1.44 0a0.72,0.72 0,1 1,-1.44 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M16.42,4.67m-0.8,0a0.8,0.8 0,1 1,1.6 0a0.8,0.8 0,1 1,-1.6 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M16.42,16.59m-1.09,0a1.09,1.09 0,1 1,2.18 0a1.09,1.09 0,1 1,-2.18 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M1.72,10.63m-0.72,0a0.72,0.72 0,1 1,1.44 0a0.72,0.72 0,1 1,-1.44 0" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M10.81,12.08m-0.9,0a0.9,0.9 0,1 1,1.8 0a0.9,0.9 0,1 1,-1.8 0" />
+</vector>
diff --git a/app/src/main/res/drawable/ic_radiation.xml b/app/src/main/res/drawable/ic_radiation.xml
new file mode 100644
index 0000000..f669bde
--- /dev/null
+++ b/app/src/main/res/drawable/ic_radiation.xml
@@ -0,0 +1,18 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M13.79,11.19c0,0.66 -0.36,1.23 -0.9,1.53c-0.25,0.17 -0.56,0.25 -0.88,0.25s-0.63,-0.08 -0.89,-0.25c-0.53,-0.3 -0.9,-0.87 -0.9,-1.53s0.37,-1.25 0.9,-1.54c0.26,-0.17 0.57,-0.25 0.89,-0.25s0.63,0.08 0.88,0.25C13.43,9.95 13.79,10.53 13.79,11.19z" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M10.19,8.06c-1.07,0.63 -1.8,1.8 -1.8,3.13H2.7c-0.4,0 -0.73,-0.34 -0.7,-0.74C2.23,7.3 3.9,4.57 6.36,2.9c0.33,-0.23 0.79,-0.1 0.99,0.24L10.19,8.06z" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M22,10.45c0.03,0.4 -0.3,0.74 -0.7,0.74h-5.69c0,-1.33 -0.73,-2.52 -1.8,-3.13l2.84,-4.92c0.2,-0.34 0.66,-0.47 0.99,-0.24C20.1,4.57 21.77,7.3 22,10.45z" />
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M16.37,20.21c-1.32,0.64 -2.8,1 -4.36,1c-1.57,0 -3.06,-0.36 -4.37,-1c-0.37,-0.17 -0.49,-0.63 -0.29,-0.99l2.84,-4.92c0.53,0.31 1.16,0.49 1.82,0.49s1.27,-0.17 1.8,-0.49l2.84,4.92C16.85,19.58 16.74,20.04 16.37,20.21z" />
+</vector>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 29a750f..c19d9e1 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,7 +1,10 @@
 <resources>
     <string name="app_name">AirMQ</string>
     <string name="map_sensor_dust">Dust</string>
+    <string name="map_sensor_air_quality">Air quality</string>
     <string name="map_sensor_radioactivity">Radioactivity</string>
+    <string name="map_sensor_help_link">What does this mean?</string>
+    <string name="map_sensor_help_title">What do AirMQ sensors measure?</string>
     <string name="map_search_action_content_desc">Search</string>
     <string name="map_my_location_content_desc">My location</string>
     <string name="map_back">Back</string>