You plug the heat pad into the Tstat, then plug the tstat into the wall, set the temperature on the thermostat, and let the sensor probe on the thermostat tell you what temperature the heat pad is being regulated at. Your best bet is probably to buy one through the internet. Below is a good web site, but there are many others. If you have anymore questions don't hesitate to hollar!

http://mgreptiles.com/