Here is how I have my CHE. I have it on a telescopic pole in a wire cage fixture with it slightly above the screen top and the probe of the thermostat connected to the screen via zip tie and dangling about 4 inches below the top of the screen. I have it dialed into roughly 83 degrees F ambient before it ticks off and it will tick on again before it hits 81. works perfect and he loves basking above his hide on days he feels frisky