Compatibility matters more than anything else when ordering hub end caps, and the NEO OS line from Stan's NoTubes serves a specific subset of their hub range. These front 20mm end caps fit Neo OS and Neo Ultimate OS hubs only, which use larger 6804 bearings (20x32x7mm) to accommodate 20mm axles for downhill and enduro forks. If your Stan's hub runs standard-size bearings rather than the OS variant, these won't work. Same goes for Center Lock rotor hubs or the newer M-Pulse platform.

The SealLock design uses a low-friction U-cup seal that snaps into place and stays secure even when the wheel comes off the bike. That retention matters on trail rides where you might need to pull a wheel for a trailside repair. The seal keeps moisture and debris out of the bearing while maintaining smooth engagement with the axle. The machined alloy construction handles the loads that downhill and enduro riding generate, and each cap carries a code number stamped into the surface for identification when you're sorting through parts bins.

The kit includes one pair of end caps for 20x110mm Boost spacing. No axle, bolt, or quick release included. The modular ecosystem Stan's built around the NEO OS shell means you can adapt the same hub to different axle standards as frames and forks evolve, which extends the useful life of your wheelset investment.