Feature:1. Premium Material: Door bell is made of premium ABS material, fire retardant, wear resistant, not easy to deform or damage, sturdy and durable.2. 2 to 1: Wireless doorbell can be used for the front and rear doors, or set separate corresponding ringtones, also can be a pager.3. 58 Melodies: Cordless doorbell with 58 melodies and 4 adjustable volume levels, LED flash is suitable for the elderly and hearing impaired.4. Long Working Distance: Transmission distance is up to 150m/492ft in open space, strong penetrating power, ensures you will never miss a visitor.5. Excellent Performance: IP44 sunproof waterproof doorbell, can withstand harsh weather conditions, effectively prolong the service life.6. Simple Installation: The installation is simple, self powered doorbell can generate electric power by itself, no wiring or battery required.Specification:Item Type: Wireless DoorbellMaterial: ABSApplication: Home, shop, office doorbell or pagerPlug Standard: AC110-240VStandard: 2 to 1Color: BlackTechnical Parameters: Transmitter:Power Supply: Self poweredSize: Approx. 90x22mm/3.54x0.87inEnvironmental Temperature: -20C to +60CTransmission Distance: Open space > 150m/492ftRF Frequency: 433MHzReceiver: Power Supply: AC110-240V 50/60HzPower Consumption: 0.25WRingtone: 58 melodiesRingtone Volume: 90dBEnvironmental Temperature: -10 to +45.Package List:2 x Wireless Doorbell1 x Indoor Unit2 x Sticker1 x User Manual