Review on Pymeter Digital Temperature Controller: Dual Probe Reptile Thermostat for Heat Mat, Cooling & Heating Pad - Ideal for Reptiles, Homebrew, Aquariums, Greenhouses, Terrariums, and Carboys by Craig Rossman

I found the instructions and display a little confusing, but it's not a light switch so that's to be expected. We have a very large air compressor with an external oil cooler that tends to overheat. I bought it to lower the oil temperature. The supercharger has a belt driven fan that draws air through an oil cooler, but the fan is not ducted so it doesn't actually draw air. I mounted a wall mounted exhaust fan directly on the radiator and connected it to the pyrometer. The fan came with such a device, but it didn't have the external sensors that this one did, so it only turned itself on or off based on room temperature, which didn't help. With this device I was able to tie one of the sensors to the oil line to get direct feedback on the compressor temperature. So true. Since I only use one outlet, a second sensor on the device tells me what the room temperature is, which I find handy. Regardless of the application, you get two separate sensor readings and displays. You can have one inside the reptile cage and one outside to see the difference. I also like that this has no sockets or labels for "heat" and "cool", just 1 and 2. Each of these can be programmed to operate in cool or heat mode. The only difference between heating and cooling is that in cooling it occurs when the sensor rises to the set temperature and turns off when it falls below it. The heating mode works in reverse, turning on when the temperature falls below the set point and turning off when it rises above it. You set an area in between. Although older home thermostats are set to a single temperature setting (they usually have a built in one degree range). Obviously, when setting up this program, no two temperatures can be the same. certain time and turn off at the same time. I found the programming display a bit confusing as there is a capital letter o next to the number of the controlled and programmable output to turn on. When you get to this point the program makes the number one looks like 10 or 20 (1 on and 2 on / 1 off or 20 off instead of 1 on or 2 on. Very pleased with the quality and versatility of the device features.