Olympia KM 210. Detector type: Electrochemical detector, Alarm decibels: 85 dB, Certification: EN 50291-1:2010+A1:2012. Power source type: Battery, Battery voltage: 1.5 V, Compatible battery sizes: AA. Width: 120 mm, Depth: 38 mm, Height: 80 mm. Master (outer) case width: 242 mm, Master (outer) case length: 116 mm, Master (outer) case height: 186 mm