If you're passionate about IT and electronics, like being up to date on technology and don't miss even the slightest details, buy  Smart Sensor for Doors and Windows Shelly  at an unbeatable price.

Colour: White
Material: Plastic
Connectivity: 
Bluetooth
Bluetooth 4.2
Voltage: 3 V
Includes: Battery
Batteries included: Yes
Battery type: Lithium
Battery: Alkaline Batteries