Universal Stopper has helped stop false alarms for over 40 years without restricting legitimate alarms. Polycarbonate protective cover helps prevent false alarms, saves possible municipal fees, disruption, evacuations, unnecessary gatherings and a loss of productivity. When the cover is lifted, a self-contained 95/105 dB warning horn sounds. Immediate attention is drawn to the area and the prankster will either run or be caught before a false alarm is pulled. Clear indoor/outdoor cover does not restrict legitimate use of fire alarm. Flush mounted cover. UL/cUL Listed, ADA Compliant.