Check the listing for details. SAFETY TECHNOLOGY INTERNATIONAL STI- 13300NC Universal Stopper - Clear. Condition: New. Listed at 55.00 USD. This universal stopper from Safety Technology International (STI) is a reliable solution for your alarm system needs. This housing unit is compatible with various models and is made in the United States. This indoor/outdoor dome polycarbonate cover protects devices such as dual action pull stations, keypads for entry systems, intercom stations, emergency buttons, electrical light switches, duplex plugs, etc., against vandalism accidental damage without restricting legitimate operation. Cover options: dome or low profile, with or without horn, flush mount, surface mount or waterproof back box models. Maximum protrusion is 4 inches deep. 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. Size:Width 5-1/2 in. Depth 2-7/8 in. Height 8-1/8 in Price listed is per unit. 12 units are available for purchase. All boxes are sealed. 1 box has a torn label. Please see last 2 pictures which show all 12 units.