The Autool MCD11027-1 is a set of HVAC temperature clamps used as an accessory for air conditioning service and diagnostic equipment. The clamps are placed around the supply and return pipes of the air conditioning system to measure the surface temperature of the pipes. The green plastic housing with spring-loaded clamp function holds the sensor securely on the pipe, while the integrated temperature sensor in the jaw forms the contact point for the measurement.

The clamps connect via the signal cable to a compatible HVAC measurement or service station. During use, each clamp records the temperature at its measurement point, after which the host device calculates the temperature difference between the two pipes. This difference provides insight into the operation of the air conditioning, such as cooling performance and refrigerant flow. The shape of the jaw is designed for round pipes, so the sensor surface rests flat against the surface for consistent measurement.