Rectangle Metal Thermostat Guard. Factory Model Number BTG-54-VL. Comes with solid metal base. Inside cover dimensions are 6-1/4" (L) X 4-3/4" (W) X 3" (D). The 190 Series Metal Thermostat Guard Kits are made of 18/22 gauge steel with baked enamel finish hey have air circulating ports on all four sides to ensure ample air circulation for proper thermostat operation. Each guard has a permanently attached eight-tumbler type lock, and each kit is supplied with a key. Key design permits use of a single key or multiple installations. Extra keys are available separately - order 40-857REPLACES BRAMEC 13002, C&R 80632, DAYTON 2E601, INTERSTATE BTG-54VLWP, WAGNER TG-54VL, WHITE-ROGERS F29-0192, MARS 70215