This high quality fan speed controller was custom made for Hydro Innovations by Grow Zone. Designed to regulate the air conditioning through the Ice Box, our thermostat controls power to the fans with separate settings for lights on and lights off temperatures. During the on light cycle, fans are sped up to full power when cooling is needed and are slowed to an idle when the cooling needs are met. During the off light cycle the fans will again speed up when cooling is needed, but they will completely turn off when the cooling needs are met. With 7.5 amps available several fans can be run by one controller.