The new and improved SMART Motion Detectors are completely wireless and run on two AA batteries, with a 30-40 foot detection range. Set them up in your upstairs and downstairs hallways or in the basement stairwell. Any motion detected will trigger your alarm system. You can also set the system in Home Mode, which deactivates the Motion Detectors so you don't trigger the system in the middle of the night. The SMART Motion Detectors also come tamper-resistant.