The Jobe Valves Topaz Detached Longtail Valve is a float-operated valve for use in automatic filling of water troughs, tanks, cisterns, etc. The longtail valve is configured for above or below water mounting for versatility. The float operates a small pilot valve, which in turn operates the main diaphragm valve. Topaz trough valves are a good choice where their high flow, compact, robust, non-corrosive construction and high level of adaptability are needed.