Features: High-strength aluminum alloy with CNC processing. Front 2 and rear 4 high-precision bearings for low friction and strong sealing. 36 holes, 120 clicks. Front: 100*9mm/100*15mm; Rear: 135*10mm/142*12mm. Fits 6-bolt disc brakes, compatible with 7-12 speed cassette freewheels. Specifications: Material: Aluminum alloy Color: Black / Red / Colorful (optional) Clicks: 120 Type: mountain bike, 6 nails Holes: 36 holes Sealed bearing: front 2 and rear 4 Compatible Freehub: 7-12 speed cassette cogs Tooth Density: 6 pawls Brake Type: disc brake Front: 100*9mm/100*15mm Rear: 135*10mm/142*12mm End Cap: 9mm / 10mm quick release 15mm / 12mm thru alxe Weight: Quick release: approx. 590g; Thru axle: approx. 485g Package List: 1 * Front Hub 1 * Rear Hub 2 * Quick Release 4 * End Cap