The Pivot Works Watertight Wheel
Collar Kit uses an internal o-ring inside the wheel spacer, sealing the gap between the spacer and axle, effectively blocking the water and helping prevent oxidation to the bearings and spacers inside your hub.
Each complete Pivot Works Watertight Wheel Collar Kit includes the watertight wheel spacers, o-rings, wheel bearings and seals, and installation is quite easy.