I have a Zoo Med Repti Therm 500R. Others probably work equally well. The 500R has two plug-in receptacles on it so you can power two heating devices. I use mine with both my UTH and with a ceramic heater from above.
The UTH plugs into the thermostat and the thermostat plugs into the wall socket. A wire from the thermostat leads to a temperature probe that you place in the bottom of your tank against the floor of the hot side. I weigh mine down by rubber-banding the probe to a small stone. The thermostat's heat setting is adjusted with a little knob on it's face.
There's no numbers listed on the thermostat though so you'll have to use a separate thermometer to set the on/off temperature.
It takes a little while for the temperature to stabilize while adjusting the thermostat and you should plan to check on your tank about every 15-30 min or so for the 1st couple of hours. After that you'll still want to check the temps once in a while to ensure the thermostat isn't stuck permanently in the off or on state.
Hope this helps! Some believe a thermostat is overkill but if you occasionally have the a/c go out or the room gets naturally hot it's nice to know you won't bake your critters alive (at least not more than necessary).
N.F.