The Jobe Valves Topaz Differential Valve is ideal for use in water tanks which are filled by a pressure system controlled water pump. The differential valve gives a level difference which is adjustable from 50 mm up to 2.5 m to minimize starting and stopping of the pumping system. The included float ball is adjustable, and it can mount in multiple positions for just the right water level. The differential valve detaches from base with 1/4 turn for easy cleaning or servicing. It is also UV protected to ensure that you don't need to worry about sun damage.