The RV Whisper Wireless Motion Sensor is mounted to the ceiling. When motion is detected beneath the sensor, email and text message alerts can be automatically sent. The RV Whisper app also shows when motion has been detected and how long since the motion was last detected. Installation on a ceiling is simple and takes only minutes. The Motion Sensor works with the RV Whisper Monitoring Station (sold separately). Up to 10 Motion Sensors can be added to a single RV Whisper Monitor Station. The Motion Sensor comes with the following: * Motion Sensor * Mounting Screws * Batteries