This version of the Evacuator Sitemaster alarm features a simple push on, twist off push button. The alarm sounds at an extremely loud 100dB which is audible from great distances. For larger or noisier areas the Evacuator Sitemaster alarms can be easily linked using 2 core wire. Combined Sounder Strobe Powerful 100dB sounder Constructed from tough and durable ABS plastic Units can be linked to increase coverage Combined Sounder Strobe Push Button Activated Push on, Twist off Supplied complete with 9v battery Link Upto 25 units Manufactured in the UK CE & UKCA Marked ADDITIONAL INFORMATION Weight 1 kg Dimensions H 280 x W 165 x D 76mm IP Rating IP55 Product Code FMCEVASMPB Power Source PP3 Sound Output (dB) 100dB Weight 1.0Kg