The Yale Easy Fit Pet Friendly PIR Motion Detectors are suitable for connection with and to extend the Easy Fit alarm systems. They are ideally placed in the corner of any room that needs protection, such as a lounge, bedroom or extension. They are also suitable for garages and outbuildings. When the alarm is set, the infrared sensor will pick up movement and activate the siren. These motion detectors are suitable for households with pets, as they will not be triggered by a pet that weighs below 27kg. However, they are not suitable for multiple pets.This pack contains the following: 1 x PIR motion detector.4 x Wall plugs and screws.3 x 1.5V AAA alkaline cells (pre-fitted).