Features: 1.The flywheel is made of high tensile steel plate, which is sturdy and durable after quenching process and tempering hardening treatment. 2.Multilayer electroplating anti rust and tooth loss design, speed change is more sensitive and smooth. 3.The shifter adopts 12 speed 1:1 technology to improve accuracy and response speed. 4.All aluminum shift lever and the coated stainless steel wire which is 2050mm / 80.7in in length are very convenient to use. 5.12 speed leg extended and directly mounted rear derailleur adopts a shadow rear derailleur design with an enlarged bearing guide wheel, which is compatible with up to 52T flywheels. Item Type: Mountain Bike 12 Speed Groupset Product Color: As Pictures Shown Product Weight: Approx. 1890g / 66.7oz Flywheel Parameters: Specifications: 12 Speed Mountain Bike Cassette Flywheel Material: High Tensile Steel Plate + Aluminum Frame Number of Teeth: 11-46T Gear Ratio: 11-13-15-17-19-21-24-28-32-36-40-46T Color: Silver Transmission Parameters: Specifications: Mountain Bike 12 Speed Transmission Material: Aluminum Alloy Shifter: 12 speed 1:1 technology to improve accuracy and response speed, all aluminum lever, coated stainless steel wire (2050mm / 80.7in in length) Rear Derailleur: 12 Speed extended leg directly mounted rear derailleur, shadow rear derailleur design, enlarged bearing guide wheel, maximum compatibility with 52T flywheel Chain Parameters: Specifications: PYC 12 Speed Chain Size: 1/2 inch x 11/128 inch 1 x Flywheel 1 xShifter 1 xRearDerailleur 1 xChain 2 x Chain Link