Stopper II protective cover has helped stop false fire alarms around the world for over 40 years, without restricting legitimate alarms. Cover mounts directly to the wall over an existing pull station. Cover consists of a clear, super tough polycarbonate shield and frame that fits over manual pull stations. Ideal for public buildings. Three year guarantee against breakage of polycarbonate in normal use (one year on electro mechanical and electronic components). UL/cUL Listed, ADA Compliant, FM Approved.