first you need to put ur accurite probe on the glass where the uth is so that u can tell how hot the hottest part is that ur snake can come in contact with. mine used to burrow down and get right on the glass.
the reptitemp 500 works good. they r only about 25 bucks. i have two and they have been working great.
the accurite tells u your temps and humidity, the thermostat controls the UTH so it doesnt cook ur snake and spike to over 100*.