The b@home contact sensor is a wireless door/window contact for the b@home system. Open/closed windows and doors can be detected by means of an internal reed contact and a magnet. The temperature in the assigned room/rooms can therefore be automatically reduced. The app can be used to set whether the temperature should be reduced (increased in cooling mode) to the ECO temperature programmed for the assigned room/rooms or whether the control should be switched off for the room (5…°C frost protection active). An open window/door is indicated in the b@home app using a symbol. Supply voltage lithium battery CR2477/BN 3V (non-rechargeable), battery life > 10 years with normal use, protection class III, type of protection: IP30, ambient temperature -10…45…°C, wall mounting on window or door frame using glued surfaces Dimensions (HxWxD): Contact sensor 62 x 19 x 29 mm / Magnet 24 x 5 x 3.5 mm