Highly recommended for gymnasiums and other areas where abuse is severe. This super tough cover is designed to protect clocks, bells and similar instruments. The unit is constructed of 9-gauge stainless steel wire. The octagon, spiderweb like shape also helps this cover take tough knocks in stride. As all STI protective covers, this Stopper is backed by a lifetime guarantee against breakage in normal use. Installation is easy and tamper resistant hardware is available