I put this in my handheld shower to slow the pressure because the pressure was so great that when it's on, the handheld is pushed away by the force of the blast of water coming out. I preferred this over an attachment and using Polytetrafluoroethylene tape. It slows down the pressure without any leaks. It works well but almost too well that the pressure slowed down significantly. I still prefer this pressure level over the blasting one previously.