Water spray nozzle is a flow controller so it creates extra pressure by flow control. It can boost pressure to some level only. If incoming water pressure from the hose pipe is low then it cannot boost the pressure very high. For insufficient water pressure from the tap (hose pipe), if you need very high pressure then you require extra water pump.
Are you still worried that the water pressure at home is weak and cannot complete the watering work, the nozzle provides you with high water pressure. Twist it further from Fine Mist mode and it will generate enough pressure to flush the floor and your car. The high-pressure nozzle lets you say goodbye to repeated flushing.
A water spray gun is a device that attaches to the end of a garden hose and controls the flow and direction of the water. It has a variety of spray patterns