Honeywell CT2800 is a programmable thermostat compatible with gas, oil, and electric systems. It features a large, easy-to-read display, weekday/weekend programming, and a fan operation switch. The thermostat can be programmed for four time periods on weekdays and two time periods on weekends, allowing you to customize your home's temperature to fit your schedule and save energy. It also has a low battery indicator to remind you when it's time to replace the batteries.