Adjust jet pressure by turning handle. Requires a 2 5/8 inch hole size. There are 5 JET BODY (CLEAR) styles available, chosen by air and water supply line sizes. A jet body includes wall fitting and gasket (#1) and nozzle assembly (#8). #7 in picture is OLD two piece nozzle that is no longer available, replaced by NEW one piece unit shown #8. COMPLETE JET is available in 1 inch air and 1 1/2 inch water sizes only.