Good morning John, I am assuming you are referring to our U2526 1/2″ hose connector with stop? This item is fitted to the end of the hose and when the accessory is removed such as spray nozzle etc, the internal fitting closes off the water flow through the hose so you can change accessories etc, without having to go and turn the tap off. You will see a red cross shaped piece of plastic in the end of the hose that shuts-off the water. I trust that this assists?