The Yale Door Position Sensor & Magnet is an accessory designed for the Yale Smart Opener, ideal for use with garage doors and gates. This replacement sensor and magnet enable you to check the status of your door (open or closed) from the Yale Home app. The sensor is battery-operated, using a single 3V Lithium CR2477 battery, which is included and offers a battery life of up to 3 years depending on daily usage. The product dimensions are 70mm x 46mm x 21mm for the sensor and 40mm x 20mm x 3mm for the magnet. The communication frequency between the Smart Opener and Door Position Sensor is Bluetooth – 2.4GHz.