Edwards 200 class 48mm Stacklight™ is a versatile signaling device that may contain up to five light modules, or four 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 with led light sources as a multi-mode device. The lenses are made from a self-extinguishing polycarbonate material and are scratch and impact-resistant.