Balboa HydroAir Slimline Teardrop style Air Control Assy Complete (White), 10-2330 has a white rotating lid with a tear drop shape in the cap. Turn to open an air port to mix air with spa jets. Slimline Teardrop Air Controls are used on many hot tubs, jetted tubs and whirlpool baths. They have a 1"" slip socket air pipe connection and require a 1-3/4"" hole size for mounting spa side. Includes gasket and lock nut for sealing up against the spa shell or cabinet.