The wireless DOOR1 sensor is easily installed on RV entry doors, RV storage doors and other doors you may want to track. The sensors requires an RV Whisper Monitoring Station (sold separately) to work. The RV Whisper monitor station collects and logs the DOOR1 data using Bluetooth Low Energy. The Door Sensors allow you to get rapid text and email alerts when exterior doors open or close. Each Door Sensor comes with the following: * Sensor * Coin-cell battery * Double-sided foam tape