Sprocket Kit Fit For Zontes Silent Durable Pinion Front Rear 14T 42T 43T ZT125 ZT150 ZT155 U U1 U2 G1 G2 Z2 GK G1X ZT KD 125 150 155 Works with ZT125 ZT150 ZT155 U U1 U2 G1 G2 Z2 GK G1X ZT KD 125 150 155;acts as full drive gear replacement set output shaft hub spline structure;allows direct mounting without extra or Built with built in mute buffer layer;lessens friction noise during city highway riding Made of solid forged blank; polished gear teeth to slow abrasion during long term use Supports 14T front 42T 43T rear tooth options;all components follow unified dimension standards