? All-in-1 with BSEN-14604 approved ? H: 25 mm ?: 95 mm ? 9V alkaline battery operate ? Over 1 year battery life ? Low battery warning signal ? Steady LED on master unit, flashing LED on slave units ? 85dB at 3 m loud tone ? Test button to test function ? Different sounds signal indicates different modes ? Memory function, hush feature, temporary delay warning signal ? Automatic self test 1 x per minute ? Easy & simple to install ? Transmission frequency 434.33 MHz ? 16 channels incl. 1 with priority ? Unlimited number of alarms Interlinkable ? No control alarm required ? Over 100m distance depending on local radio conditions