Lightweight 1st gear drive flange includes factory-pressed (non-replaceable) high-quality German one-way bearing, hand-ground for maximum running precision and strength. The one-way bearing must be regularly serviced, cleaned, and oiled (we recommend using # 106231 HUDY One-way Lube). Designed to be used with new small 2 speed. CNC-machined from tough Swiss 7075 T6 alu.