RWM160 smoke alarm, extra flat, HxWxD 23 x 115 x 115 mm, white. Supplied = assembled. Height = 23 mm. Width = 115 mm. Depth = 115 mm. Colour = white. Product type = smoke alarms. 10 year battery. Ambient light detection, reduction of flashing at night. Automatic self-test. At just 2.3 centimetres in height, our RWM160 smoke alarm is an ultra flat designer highlight and provides fire safety in a radius of around 40 square metres. Protect yourself, your family, the family guinea pig, the dog and everything else that you value, and install smoke alarms! Our RWM160 optical smoke alarm, for example, which sounds an 85 decibel alarm as soon as smoke particles enter its measuring chamber. The built-in lithium battery lasts for around ten years. If the lithium battery runs out of power, a beeping sound will alert you. The only thing you should do is a function check once a month. The user friendly, large test button on the smoke detector makes this easy to carry out in rooms with high ceilings