This motion detector alarm set has everything you need in a home security system: two compact motion sensors that "remember" when an intruder has passed, a key pad for security code entry, and a panic button. The motion sensor detector alarm uses infrared technology to detect motion in a 60 degree arc and up to 16 ft. away. Use the convenient key-chain remote to arm and disarm the motion detector on this durable, portable motion detector alarm set.