With an integrated temperature sensor and photocell this Honeywell timer is suitable for controlling outdoor loads such as engine block heaters and outdoor lighting. When the temperature sensor mode is enabled the timer will turn the connected load on when the temperature falls to a user-selectable 12 degrees Celsius (10 degrees Fahrenheit), six degrees Celsius and (21 degree Fahrenheit), or three degrees Celsius (37 degrees Fahrenheit). The photocell mode will activate the scheduled program at dusk and turns off the timer at the designated time. A sunset/sunrise mode will turn the timer on at dusk and off at dawn. It features a weatherproof housing, easy 3-button programming, and the programming will be preserved in the event of power loss. The timer is rated for a maximum load of 1,800 watts.