Hope pro 4 mtb rear hub boost 148mm x 12mmhope hubs have proven their reputation for bulletproof quality time and time again thats why hope pro 4 mtb rear hubs are the benchmark for disc brake compatible rear hubs features4 pawl ratchet with 44 tooth engagement 8 2sealed stainless steel cartridge bearingsmachined from forged 2014 t6 aluminium billetboost 148mm hub width and designed to take a 12mm thru axlestandard 6 bolt disc fittinglarger spoke flange to enable stiffer wheel buildsunsu