the ring base allows you to mount the frame around the existing thermostat without disturbing the wiring

this specific part is tailored for 5-inch diameter actuators

What is the difference between the K19AT-36 and the K19AT-36H

Whether you are performing a seasonal tune-up or a corrective repair

Look for soot accumulation around the blower flange

Johnson Controls T-4000-3140 Plastic Cover the ring base allows youProfessional grade Johnson Controls T 4000 3140 plastic covers are engineered for high performance pneumatic room thermostat applications. This horizontal mount faceplate is compatible with nearly all T 4000 series instruments, excluding the T 4100 and T 4600 models. Constructed from durable, white thermoplastic, the T 4000 3140 features a built in Fahrenheit Celsius thermometer to provide clear ambient temperature feedback for facility maintenance