Waterway Venturi Air Control Dial
This top-side controller allows you to regulate the amount of air that is mixed with the jet water. Jet pressure is increased by adding more air and vice versa.
Recommended Spa Hole Size: 1-5/8".
Accepts standard 1 inch I.D. plumbing (1" I.D. plumbing measures approximately 1-5/16" O.D.)