The Yale Security Easy Fit Door / Window Contact and Magnet are suitable for use with the Easy Fit alarm systems. They have a lightweight, compact and slim design and can be fitted to the interior of main access points in and around the home. When the door or window is opened, the contact and magnet lose connection, which activates the alarm. This device is particularly suitable for homes with pets, where motion detectors could accidentally be activated. The pack contains: 1 x Door/window contact.2 x Wall plugs and screws.2 x Adhesive pads.1 x CR2032 battery (fitted).