This silicone air tube attaches onto the Moto Massage Jet If it breaks or splits, the Moto Massage Jet won't receive the proper air mixture which in turn will cause it to stop traveling The o-ring (33020) and the cap (30723) are included

Silicone air tube used on the Dual Moto-Massage Jet replacement (73542) for select Hot Spring Models from 2005 to 2018, and the Limelight Gleam from 2013 to 2017 It comes with the O-Ring (33020) and Plastic Cap (30723)