HIGH PERFORMANCE TRANSMITTER: Ultra-low power consumption; uses a lithium battery that boasts 3 year maximum lifespan; IP55 dustproof and waterproof; working temperature ranges from -4 °F-140 °F; withstands various harsh weather conditions 1300 FT / 400 M WIRELESS RANGE: 2 plug-in receivers included; will not interfere with other equipment in your home or those of your neighbors; ensures that you will never miss any visitors, even if you are several rooms away