Get reliable automatic irrigation control when you don't have AC power with the ESP-9V Series Battery-Operated Controller. The ESP-9V's waterproof case and dual-sealed battery chamber ensure long life even when installed in a wet, muddy valve box. In harsh environment testing the ESP-9V outlasted the competition by 70%. After being submerged in water at alternating extreme hot and cold temperatures the ESP-9V was still going strong after the competition failed in less than two days.