Small GARDENA System Fitting, but what an effect. 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 and 16 mm (5/8") hoses.