Specification: Item Type: Wireless Doorbell Material: ABS Application: Home, Shop, Office, Doorbell or Pager Transmitter: Power source: self-generated Ambient temperature: -20-+60 Transmission distance: Open space > 150M RF Frequency: 433MHz Destination: Power Supply: AC110-240V 50/60Hz Power Consumption: 0.25 W Ringtone: 58 Ringer volume: 90 dB Ambient temperature: -10-+45 4-Level Volume Adjustment: The doorbell chime provides 58 melodies to choose from, 4-level adjustable volume, louder than 90dB, meet your different needs. Adjust the volume according to the individual to solve the volume problem. Long Range Wireless Doorbell: The transmission signal of wireless doorbells for home is up to 150m in an open area , long transmission distance, it can be safely applied to various scenarios, such as apartments, houses, offices and other places. Multi-purpose: Not only a doorbell, but also can be a pager, suitable for babies who sleep alone, the elderly, pregnant women. The wireless home doorbell has IP44 sun and water protection, can withstand harsh weather conditions. The working temperature is -10-+45. Easy to install: The installation method of this wireless doorbell is very simple, just plug the receiver into a power source. power supply and attach the transmitter to the wall with the accompanying sticker. No wiring or battery required.