Biltin Bearings are the first precision bearing designed for skateboarding that incorporates an integrated spacer and washer. The perfectly faced inner races provides precise spacing and perfect alignment so that the locknuts can be snuggly tightened without pinching or binding the bearings. The bearings work together to more evenly share the sideloads and keep your wheels flat on the ground for better wear. This patented system is guaranteed to give you the fastest and strongest bearings on the planet. They fit all skateboard wheels that use the industry standard .400" spacing (10.16mm). Tested by the world's fastest skateboarders in the most demanding conditions, Biltins provide unparalleled performance in all types of skating. They are also the easiest bearings to use, making those nasty little washers and annoying spacers a thing of the past. Designed to be easier to maintain than other bearings, Biltins are simply the best and fastest skateboard bearings on the market today.