This pair of front end caps is designed to fit E-sync hubs when used with RockShox/SRAM-specific Torque-Cap 15mm thru-axle forks. These 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. Torque-Cap end caps have the same 15mm inside diameter as other systems, but the outside diameter is larger (31mm), making these end caps only compatible with Torque-Cap-compatible forks. Fits 6-bolt E-sync, Neo, and Neo Ultimate hubs. Not compatible with Centerlock versions of E-sync, Neo, or Neo Ultimate hubs. Not compatible with E-sync OS and Neo OS hubs. Not compatible with M-pulse hubs.E-sync:- E-sync hubs are built to last, including under the higher torque and weight of eBikes. A 6066 alloy shell, heat-treated steel ratchet ring, reinforced pawls, and full Enduro bearings rovide brute strength, while 8.18° engagement provides the speed.