DIG RBC8000 - Single Station Battery Powered Irrigation Timer / Controller With 3/4" Anti-siphon Valve - Watering Timer Powered by two AA alkaline batteries with a safe period of 60 seconds to replace without losing the program (batteries not included) Watering flexibility with a selection of watering frequencies and four start times Energy conservation; after fifteen minutes the timer screen is turned off automatically Fully waterproof Battery life up to three years