The GARDENA 2 hour water timer is perfect for controlling scheduled water flow.  Easy to set, using the large rotary knob, the watering time can be set for between 5 and 120 minutes, where after the water timer switches off automatically.
It has an adjustable water flow rate and comes with a manual override function for permanent water flow.  Adapters for 12.5mm and 19mm tap connectors are included.