Rectangle Transparent Thermostat Guard. Factory Model Number BTG-UK. Comes with solid and ring type base. Inside cover dimensions are 8-1/4" (L) X 5" (W) X 3-1/2" (D). The 190 Series Thermostat Guard Kits are designed to give complete enclosure protection to the thermostat. They 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 40-857.REPLACES BRAMEC 13012, C&R 80213, DAYTON 2E706A, INTERSTATE BTG-UK2P, WAGNER TG-UK2, WHITE-ROGERS F29-0198, MARS 70220