The Simpled Door Sensor enables your Simpled Smart Locks to lock automatically when your door is pulled closed.With a Simpled door sensor and WiFi Bridge (sold separately), you receive instant notifications to your smartphone once the door is opened or closed. For a stable connection, please ensure no obstacle is between your door sensor and Simpled WiFi Bridge.No Need to use complicated tools for installation, it comes with a 3M glue strip for easy fitting.Low power consumption boasts more than one year of battery life.