Honeywell Home Rth221B1039 1-Week Programmable Thermostat Product Description This easy-to-operate 1-Week Programmable Thermostat helps make your home comfortable exactly when you want it. Programmable for one week, it lets you customize your schedule with four options ? ?wake?, ?leave?, ?return?, and ?sleep? ? for precise temperature control and added comfort. Simple step-by-step instructions included with the thermostat make DIY installation easy. From the Manufacturer A Honeywell programmable thermostat can save you significant money off your energy bill. You set it up to adjust the temperature when you are away or asleep---times when you don?t necessarily need to heat or cool your home to optimum comfort---and your heating and cooling equipment runs less. This one-piece thermostat has one easy program for all days of the week (4 periods - wake, leave, return, sleep). Simple and effective use and performance. Plastic Imported ONE WEEK PROGRAMMING: Set one identical program for the entire week with four program periods per day including wake, leave, arrive and sleep. PRECISE TEMPERATURE CONTROL: Precise temperature control of plus/- 1 degree Fahrenheit DIGITAL DISPLAY: Easy-to-read digital display with an intuitive interface for one-touch access to setpoint temperature EASY INSTALLATION: Easy to install yourself and basic operation keeps programming simple REMINDERS: Built-in battery change reminders (2 AAA batteries are required for operation) SET POINT RETENTION: Set point is retained in memory in the event of a power outage DISPLAY OPTIONS: Fahrenheit or Celsius; 12 or 24 hour clock. Note: This thermostat is not backlit. OVERRIDE OPTIONS: Permanent and temporary override capability COMPATIBLE WITH: Heating, cooling and heat pumps without auxiliary heat options Does NOT work with electric baseboard heat (120-240 V), heat pumps with backup, or multi-stage heating/cooling. For indoor use only.