Primo N4FL Front Hub material: 6000 series aluminum hubshell | CrMo Center axle | Chromoly 3/8 inch bolts axle size: 15mm hollow center axle with 3/8 inch bolts spoke holes: 36H bearings: 6902 2RS (2) color: black additional information: must be laced with normal spokes 194mm 4-cross pattern flangeless design to prevent damage 3/8"x24tpi chromoly axle bolts 2 integrated plastic hub guards