Thanks to the zinc die cast sleeve the Hozelock metal AquaStop is strong, durable and scratch resistant. The large bump ring protects greenhouses and cars from damage The Aqua Stop connector incorporates an internal valve that stops the water flow when an accessory (eg a spraygun ) is disconnected. This saves you having to go back to the tap to turn the water off when you are switching between accessories. It also helps you save water in the garden because it stops the water flow so less water is wasted. Suitable for use with all 12.5mm 1/2" and 15mm 5/8ths" hose All internal parts are made from ultra tough engineering plastics for a long leak free life The connection to the tap is guaranteed secure up to 10 bar, thanks to a triple locking system The sleeve is easy to use even when wet because of the twin soft touch pads The hose is firmly connected thanks to barbs that connect with the inside and outside of the hose Hose kinking , Hose swelling, and hose leaking at the connection point with the fitting is virtually eliminated due to the ingenious flexible hose-tail on the nut