This pair of front end caps is designed to fit 6-bolt E-sync hubs when used with 12mm axles. The included end caps are also compatible with Neo and Neo Ultimate hubs. The end caps feature a low-friction U-cup seal that snaps into place and stays secure even when your wheel is removed from your bike. Fits 6-bolt E-sync, Neo, and Neo Ultimate front hubs. Compatible with forks that use a 12mm axle. Not compatible with Centerlock or OS versions of E-sync, Neo, or Neo Ultimate hubs. Not compatible with M-pulse hubs.