Lux Products TX500E Smart Temp Programmable Thermostat The TX500E does not come with a backlight 4 pre-programmed periods per day, Keyboard lock Temporary override and manual hold, 3 year warranty Selectable fahrenheit/celsius setting, Adjustable temperature swing (differential) Easy installation, Easy to use, Easy to read display, Air filter monitor, Optional wall plate 4 pre-programmed periods per day, Keyboard lock Temporary override and manual hold, 3 year warranty Selectable fahrenheit/celsius setting, Adjustable temperature swing (differential) Easy installation, Easy to use, Easy to read display Air filter monitor, Optional wall plate