STI’s Stopper II (STI-1100) protective polycarbonate cover is designed to decrease false fire alarms. The cover fits over manual pull stations, and when lifted, a loud warning horn sounds locally. Immediate attention is drawn to the area, and the prankster will either run or be caught before a false alarm is pulled. It offers excellent protection against false fire alarms, physical damage (both accidental and intentional), dust and grime and does not restrict legitimate alarms from being activated. The Stopper II is UL/cUL Listed and ADA Compliant and has a three-year guarantee against breakage of polycarbonate in normal use (one year on electro mechanical and electronic components).