Review on 🌡️ InterDynamics Certified AC Pro Automotive Air Conditioner Thermometer Test Kit, 0-220°F Reading Range, Holder and Clip Included, Model TH-27 by Mikey Jackson

This basically does what it's supposed to do. My particular unit was about 4 degrees warmer, which is pretty significant. I don't think they are properly calibrated from the factory. Fortunately, the solution is simple. Take a glass, fill it with ice and fill the ice with water. Insert a thermometer, stir and allow to equilibrate. As long as ice and water coexist, the temperature is exactly 0 C or 32 F. Look at the temperature that the thermometer reads. When it's off, take a 10mm wrench and put it on the nut under the temp head. Hold the thermal head in your hand while holding the nut with a wrench and turn the head in any direction until the temperature reads 0°C or 32°F.