Frighten away intruders without installing an expensive security system. The miniAlarm Motion Sensor is a standalone motion detector with a built-in 130-decibel alarm that protects your home when you're away. The miniAlarm Motion Sensor is powered by AA batteries (sold separately). Mount the miniAlarm Motion Sensor on a wall or stand it up in the area you want to monitor. Arming the miniAlarm is easy, thanks to the included keychain remote. Once armed, the miniAlarm uses a passive infrared (PIR) beam to detect movement up to 20 feet away. If triggered, the loud alarm will blare for 30 seconds before resetting automatically, ample time to incite would-be intruders to scatter! Use the included remote for quick arming and disarming. With its 30-second exit delay and 4-second entry delay, you'll have ample time to enter and exit your home without setting off the alarm. If you have more than one family member who will be setting the system, additional keyfobs are sold separately. An added alarm output can be used to trigger a home alarm system (sold separately). A Mini Alarm Motion-Sensing Kit is also available. This set comes with the MiniAlarm Motion Sensor w/Remote Control but also includes an auto-dialer that automatically calls your cell phone when motion is detected.