The SB150-2, 3 & 4 combined sounder beacon range has been approved for use in potentially explosive atmospheres and very harsh environmental conditions. Typical applications are Oil and Gas,On-shore and Offshore, Chemical,Petrochemical, Refineries &Marine locations etc. The unit incorporates a three stage alarm option with 60 tones to choose from. The units offer a combined audible & visual warning signal with the option of either a junction box, allowing extra space for ease of installation & final connections. This is particularly helpful if the unit is to be installed into a fire or telecom system where additional cabling is required to monitor external devices or a push button unit for manual activation.The units are mounted on a heavy duty 316 stainless steel, pre-drilled, mounting plate & the units are pre-wired asstandard, so that on the basic modela single input operates both unitssimultaneously.