The GARDENA Water Stop is connected to the hose outlet. When a connecting device is disconnected, e.g. a nozzle or sprinkler, it stops the water automatically; when a device is connected, the water flows freely again. This saves a trip to the tap when changing accessories. The Water Stop is suitable for 19 mm (3/4") hoses. POWER GRIP: Specially shaped sleeve nut for a very tight fit and trouble-free assembly. Thanks to the grooved soft plastic grip, the GARDENA Hose Connector lies well and securely in the hand. The Hose Connector is protected by a rubber ring that prevents damage.