GB notice: the KMC is 100% Brand new and original, please choose correct speed for your bike. KMC X8 6/7/8-Speed Chain Model: X8 Dimensions: 1/2'' X 3/32'' Pin length: 7.3mm Link: 116 Links Weight: about 330 grams Color: Silver/Gray Missing Link: 8R/CL573R Compatible: 6/7/8-speed Feature -Superior Shifting Performance -Extremely durable -Non Directional -Nikel Plated KMC X9 9-Speed Inner Plate Chamfering Chain Model: X9 Dimensions: 1/2'' X 11/128'' Pin length: 7.3mm Link: 116 Links Color: Silver/Gray Connector: Missing Link 9R/CL566R Compatible: 9-Speed Drivetrain System Feature -New X-Waist guide angle quickly occludes smoothly -Unparalleled precision adjustment -Simple and quick to do it once -Patented double X bridge design -SP wear resistance technology -Fungus riveting technology -Inner chain guide angle design -Improve shifting performance KMC X10 10-Speed Road/Mountain Bike Chain Model: X10 Dimensions: 1/2'' X 11/128'' Link: 116 Links Color: Silver/Gray/Gold Connector: Missing Link 10R/CL559R Compatible: 10-Speed Drivetrain System Feature -Super Strong Fitting Force, Hydraulic Riveting Technology -2X-SP Wear Resistance Technology -Patented Double X Bridge Design, Precise and Agile Shifting Performance -The Guide Angle Design of The Outer Chain Piece Increases The Smoothness of Shifting -The Guide Angle Design of The Inner Chain Can Improve The Speed Change Performance KMC X11 11-Speed Road/Mountain Bike Chain Model: X11 Dimensions: 1/2'' X 11/128'' Link: 118 Links Color: Silver/Gray/Gold Connector: Missing Link 11R/CL555R Compatible: 11-Speed Drivetrain System Feature -Super Strong Fitting Force, Hydraulic Riveting Technology -2X-SP Wear Resistance Technology -Patented Double X-bridge Design, Precise and Agile Shifting Performance -The Guide Angle Design of The Inner Chain Can Improve The Speed Change Performance -The Guide Angle Design of The Outer Chain Piece Increases The Smoothness of Shifting KMC X12 12-Speed Road/Mountain Bike Chain Model: X12 Dimensions: 1/2'' X 11/128'' Link: 126 Links Color: Silver Black Connector: Missing Link 12/CL552 Compatible: 12-Speed Drivetrain System Feature -Super Strong Fitting Force, Hydraulic Riveting Technology -High Rigidity, Instant Transfer Efficiency, Maintain Efficient Transmission -2X-SP Wear Resistance Technology -Patented Double X-bridge Design, Precise and Agile Shifting Performance -The Guide Angle Design of The Inner Chain Can Improve The Speed Change Performance -The Guide Angle Design of The Outer Chain Piece Increases The Smoothness of Shifting