This hinged cover from STI can take hard knocks in stride while helping to protect smaller-sized electrical units. Both the cover, adapter plate and its hinges are molded of super tough clear polycarbonate material. The Bopper Stoppercover (STI-6518) and the now included adapter plate provides a solid back for surface-mount applications. The cover comes with installation screws and gasket. The device features a stainless-steel torsion spring to keep the cover closed. The polycarbonate Bopper Stopper is backed by a three-year guarantee against breakage in normal use.