The window door sensor is compatible with the CPVAN CP8 Home Security System..Easy to install in two steps - simply peel and stick double-sided adhesive and install on door and window frames. (Adhesive and CR2032 battery included.).The window sensor door sensor will automatically trigger the receiver when the door/window is opened and get real-time alert notifications..With no signal interference, the transmission distance is up to 260 feet in open areas. Combined with the 125dB external siren of the CP8 kit will scare away any intruders..When the sensor battery is low, the indicator light will keep flashing. Enable to receive APP low battery alarm notification to remind you to replace the battery in time.