Utilising proven Swiss-Made hardened chromium steel alloy balls, the races of th Kwik Swiss Nitride bearings-the surface where friction is created with the alloy balls - are coated with an imperceptibly thin coating of Titanium Nitride to produce the fastest and longest roll available today. And you'll be able to relas and enjoy that roll right away because Kwik Swiss Nitride bearings come with XK1 Lube already applied for a bearing that is as easy to care for as it is to enjoy.