The Thermostat Only, 120/240V - Fits T10000R, T30000R, T40000R Panels These Freeze Protection Controls Are Designed To Protect Pool And Spa Equipment And Plumbing Against Freeze Damage. They Turn The Pump And Heater On When The Outdoor Temperature Drops Below The Temperature Set By The User-Adjustable Thermostat. Models Without Timer Connect To A Timing Or Switching Device And They Control Operation Of The Equipment, As Well As Protect It Against Freeze Damage. Models With Timer Provide Both Automation And Protection For The Equipment