Surly Ultra New Axle Kits are for upgrading the internals of your existing Surly New hubs or replacing the internals on your Surly Ultra New hubs. -Compatible with Surly New hubs (upgrade kit) and Surly Ultra New hubs (replacement kit) - Each kit contains an axle, two 6901 cartridge bearings, two aluminum dust shields, two stainless steel cones, two stainless steel 6x1mm bolts, and two stainless steel bolt washers - Axle is quick release and bolt-on compatible; bolts included, QR is NOT included - Standard Surly New hubs come stock with 7901 bearings; this kit uses 6901 bearings which are non-angular