Item was an easy replacement for older style eyeball with retaining rings. I would suggest the install tool if you have an older pool the threads can make it hard to get the outer ring flush with pool wall. (a rubber strap wrench will also work) I purchased 3/4, 1/2 and 3/8 eyeballs to install in my baja shelf and love seat areas. The love seat had 4 @ 1" eyeballs and air intakes to make it more like spa jets. When I installed the smaller eyeballs the air didn't mix into the returning water, I had to stay at 3/4 or 1" eyeballs. I have a 3 hp water feature pump for the waterfall and the spa jets.