Features： 1、10 Speed for Mountain Bikes: 10 speed has always been a requirement for mountain bikes, and single sprocket has become the trend of lightweight and wide gear ratio. 2、Switch to 10 Speeds Bike: To match the value of DIY bikes, most of the bikes you buy from other brands are 7, 8 or 9 speeds, these allow you to change/upgrade them to 10 speeds in one package. 3、A7 Gear Lever: Speed is 1x10, adopting 1:1 technology, precise and quick response, made of sturdy luminum gear lever, transmission line with ultra low friction coating technology. 4、A7 Rear Derailleur: Speed: 1x10, enhanced damping technology to effectively reduce chain jitter, for giant sprocket 50T, shadow RD bevel design, large bearing pulley. 5、Package List: 1 x shifter, 1 x 42T flywheel, 3 x flywheel accessories, 1 x 36T disc, 1 x 10 speed chain, 2 x chain link head, 1 x tail hook, 1 x screw, 1 x accessories. Specification： A7 Shift Lever:  Speed: 1x10 Feature: 1:1 Technology, Precise and Quick Response Material: Aluminum Shift Lever Shift Cable with Ultra Low Friction Coating Technology A7 Rear Derailleur: Speed: 1x10 Feature: Enhanced Damping Technology to Effectively Reduce Chain Jitter Shadow RD with Slant Design Large Bearing Pulley Cassette: Tooth: 11-42T  Chain Guide Groove Feature: Lightweight and Durable Material: Aluminum Alloy Bracket 42T: 11-13-15-18-21-24-28-32-36-42T  Chainring Tooth: 36T BCD104 Color: Black (Default) Material: Aluminum Alloy 7075 HV: 15+ Chain: Speed: 10 Speed  Section: 116L Color: Silver Package List： 1 x Shifter 1 x 42T Flywheel 3 x Flywheel Accessories 1 x 36T Disc 1 x 10 Speed Chain 2 x Chain Link Head 1 x Tail Hook 1 x Screw 1 x Accessories