Version selection: 1. If there is no Neutral line in your home, please choose the "wall" model. 2. If you have a Neutral line at home, please choose the "zero fire" model. 3. If you use multi-functional WiFi gateway at home, please choose "wireless" Features : * Cannot be wired, only can control smart bulb or light through ZigBee * Portable, realize controlling everywhere * Can be used as a key doorbell * SOS emergency call * Defending and withdrawing function * Wireless frequency: 2.4GHz ( 2400 - 2483.5MHz ) * Wireless connection: ZiGBee * Built-in CR2032 battery * Please download the Mi Home APP in Google Play or APP Store Description Note: The wall switch can connect the wire, can control any bulb throught the wire; while the wireless key cannot wired, only can control smart bulb or light through ZigBee. 2) Aqara Smart Wall Switch D1 (No Neutral) Single Rocker Model: QBKG21LM Dimensions: 86 x 86 x 42.85mm Wireless Connectivity: Zigbee Rated Voltage: 220V--, 50Hz Rated Power: Max 800W, Min 3W Operating Temperature:0°C~40°C Operating Humidity: 5~95% RH. No condensation Double Rocker Model: QBKG22LM Dimensions: 86 x 86 x 42.85mm Wireless Connectivity: Zigbee Rated Voltage: 220V~，50Hz Rated Power: Max 1600W, Min 3W Operating Temperature:0°C~40°C Operating Humidity: 5~95% RH. No condensation Triple Rocker Model: QBKG25LM Dimensions: 86 x 86 x 39.85mm Wireless Connectivity: Zigbee Rated Voltage: 220V~, 50Hz Rated Power: Max 1600W, Min 3W Operating Temperature:0" C~ 40 C Operating Humidity: 5~95% RH. No condensation 3) Aqara Smart Wall Switch D1 (With Neutral) Single Rocker Model: QBKG23LM Dimensions: 86 x 86x 42.85mm Wireless Connectivity: Zigbee Rated Voltage: Max 10A220V~, 50Hz Rated Power: Max 2200W Operating Temperature:0" C~40" C Operating Humidity: 5~95% RH. No condensation Double Rocker Model: QBKG24LM Dimensions: 86 x 86 x 42.85mm Wireless Connectivity: Zigbee Rated Voltage: Max 10A220V~, 50Hz Rated Power: Max 2200W Operating Temperature:0" C~ 40 C Operating Humidity: 5~95% RH. No condensation Triple Rocker Model: QBKG26LM Dimensions: 86 x 86 x 39.85mm Wireless Connectivity: Zigbee Rated Voltage: Max 10A220V~, 50Hz Rated Power: Max 2200W Operating Temperature:0" c~ 40 C Operating Humidity: 5~95% RH. No condensation