This part is specifically designed to replace the internal seal of your 1" Waterway air control valve (Star, Classic, Round or True Seal, for example) if it is damaged.
Dimensions
Outer diameter: 32 mm
Inner diameter: 21 mm
Height: 12 mm
Part numbers
Waterway: 711-2100
Passer bl.a noen modell fra Vikingbad, Hydrospa, Dreammaker spa