ShowerSmart’s water control device works with all showerheads that connect to a standard shower pipe. A wave of the hand turns the water to the showerhead on, while another wave turns it off. It is ideal for shampooing, lathering and shaving. There is no reduction in water flow and no change in shower water temperature. When used with a low-flow showerhead, it can reduce unit shower water use by up to 80%, the company stated.