Edwards 200 Class 36 mm StackLight™ is a versatile signaling device that may contain up to six light modules or five light modules with one sounder module in a single, integrated stack. The sounder module has been designed so that it is always in the top position. The lens modules are available as steady-on, LED light sources. The lenses are made from a self extinguishing polycarbonate material and are scratch and impact-resistant.