The Watts 88005629 APEX (XFTE114) 1 1/4" XtraFlo Top Entry Full Flow Diaphragm Activated Trough Valve with Float efficiently controls water levels in your trough. The float valve features a 1" water level differential between opening and closing, allowing for full-flow operation while reducing pump overload. From the manufacturer: The armless valve on this product replaces more traditional brass arm- style trough valves. In the open position, it operates at full flow to reduce wear and tear on the pump while also saving electricity. The diaphragm closes softly to prevent water hammer, the banging noise that can occur when water quickly stops or changes direction. A unique self-cleaning mechanism pushes the pin out of the jet center tip to remove accumulated debris.