For serious racers shopping for smart fat cost savings and optimized rotating weight, XRAY's brand new optional lightweight 1st gear drive flange created from 7075 T6 aluminum is strategically lightened (compared to the standard #335530 flange) to lessen rotating fat without sacrificing strength or durability. Includes factory-pressed top-notch German 1-way bearing, hand-ground for maximum running precision and power. The 1-way bearing is non-replaceable as soon as exhausted, so it must be regularly serviced, washed, and oiled frequently (we recommend using #309580 One-way Lube). Orange color.