Fox Polartec Skull Cap - Black - One Size Fits All Exclusive They are designed to be

They are designed to be used with Presta tubeless valves

Installs bearing sizes:

The system requires the use of the B-Rad mounting bases

Hexagonal shaped aluminium tubing ensures low flex and no rotation

Fox Polartec Skull Cap - Black - One Size Fits All Exclusive They are designed to beKeep your noggin toasty during those cold days on the trail. The Fox Polartec Skull Cap is designed to fit under your helmet and provide an extra layer of warmth for your head and ears. The minimal yet durable Polartec material provides plenty of warmth with a comfortable fit to help keep your temperature regulated on cold ride days. Features: Designed with Polartec fabric to keep your head warm on the coldest days on the bike Polartec fabric actively