Honeywell's touch screen 7-day programmable thermostat provides maximum flexibility for busy lifestyles. You set it up to adjust the temperature when you are away or asleep during times when you don't necessarily need to heat or cool your home to optimum comfort, and your heating and cooling equipment runs less. The RTH8500D features a green backlit touch screen interface with simplified programming and easy to follow text instead of symbols. Exclusive Honeywell Smart Response Technology continually adjusts the pre-heating/cooling of your home so you are comfortable at your programmed times. It also automatically determines if your home needs heating or cooling to provide maximum comfort. Universal compatibility means it works with virtually all system types.