Proven effective for over 40 years, this protective polycarbonate cover has been helping to stop false fire alarms around the world, without restricting legitimate alarms. When cover is lifted, a loud warning horn sounds locally. Immediate attention is drawn to the area before a false alarm is pulled. The clear cover does not restrict legitimate use. Offers excellent protection against physical damage (both accidental and intentional) and against severe environments inside and outside. The tough cover is ideal for schools, colleges, hospitals, nursing homes, stores, hotels and public buildings of almost every kind where there is a threat of false alarms. Back box rated to NEMA 3R Standards. UL Listed, ADA Compliant.