The 25mm QCV is designed to be installed in the ground so that the poly cap is just below "Mower" level. The QCV is attached to a buried water supply line via the 25mm BSP male threaded inlet. The QCV has an internal valve that is normally closed so that water does not leak out. To activate the valve, lift up the flipcap and insert the "KEY". On the top of the key you can have a sprinkler, a hose outlet or any other 25mm fitting as the key has a 25mm male BSP outlet. When the key is inserted, the internal valve is automatically opened and the water flows out through the key.