You hold it in your hand and use your palm to press the trigger on the handle, which activates the flow of water. To release the trigger, simply release pressure in the palm of your hand. You can also control the flow of water by controlling how far you press the trigger. They have many moving parts and are therefore more prone to failure than other types of nozzles. If you decide to get a pistol grip, make sure you buy the best quality you can afford.