The pro 4 front hub qr axle from hope is the benchmark for a disc compatible front hub with hopes proven reputation for bullet proof quality you have the security that this will be the heart of a strong and reliable wheel it runs on sealed stainless steel cartridge bearings and a qr axle the hub shell is machined from forged aluminium billet with standard 6 bolt disc mount and a large diameter flange available in black orange red or purple with 32 spoke holes