300m Wireless Range: Doorbells have two bell receivers with plug-in device, doorbell up to 250-300m in a fault-free environment, through security doors, walls up to 5-80m (depending on the situation) Dust, Water and Moisture Resistant: The radio doorbell transmitter is waterproof according to IP55 and can be used outdoors in the freedom of rain or snow and ambient temperatures from -20 C to 60 C. 45 Ringtones, 4 Volume Levels: The wireless doorbell offers a large selection of 45 ringtones for your personal taste of the doorbell receivers provide a rich, clear sound. The wireless doorbell has 4 adjustable volume (including mute switch) with adjustable levels from 0 dB to 110 dB. LED - Blue Flashing Signal: In addition to the ringtone, a visual signal also appears. When the bell is pressed, a blue LED circle flashes, which is clearly visible in the dark. Easy Installation: The doorbell can be easily installed by installing the Bell button without wiring the wall. Specifications: Size: Doorbell: 103*60*50mm; Doorbell Switch: 80*45*20mm; Weight: Doorbell: 76G; Doorbell Switch: 50g; Color: Black; Flashing Light Color: Blue; Transmission Range: 250-300m; Ringtones: 45 Kinds; Volume: 0db - 110db; Power: 0.25Watt; Packing List: 1*Doorbell Switch; 2*Two Doorbells; 1*Manual;