I highly recommend removing the water restricter before you mount this. Save yourself some time & plumbers tape. Check the height of your shower head because if it is up high like mine & you are short, like me (5'1") it is very difficult to turn the knob for adjustments. I have to stand on my tippy toes & don't see me doing this when I'm older. Other that that it works great, only when the restricter is removed, unless you like low pressure. Most of us don't. It only prolongs the shower so does it really save water?