For serious racers hunting for smart fat cost benefits and optimized rotating fat, XRAY's new optional lightweight 1st gear drive flange made from 7075 T6 aluminum was strategically lightened (set alongside the standard #335530 flange) to lessen rotating fat and never having to sacrifice strength or durability. Includes factory-pressed top-notch German 1-way bearing, hand-ground for optimum operating accuracy and energy. The 1-way bearing is non-replaceable the moment exhausted, so that it needs to be frequently serviced, washed, and oiled frequently (we suggest making use of #309580 One-way Lube). Orange color.