Guard Dog GSGDDK1000SL : Introducing the Guard Dog DoorKeeper, your ultimate door security enhancer. Constructed with robust 20-gauge steel, its purpose is to increase protection on both hinged and sliding doors thwarting even the most forceful intrusions.The adaptable system of the DoorKeeper ensures it adjusts to accommodate most of the standard sized doors. It\'s engineered with a top yolk pin that can be conveniently removed so it can secure sliding doors as well.