Upgrade your cycling experience with the 12 Speed Mountain Bike Groupset by SPYMINNPOO. This premium groupset features a precise rear derailleur design with a carbon fiber guide plate for improved performance and compatibility with up to 52T flywheel. Crafted with all-aluminum shifter lever and coated stainless steel cable for durability. Enjoy smooth gear shifting with the high tensile steel plate flywheel and multi-layer electroplating treatment. The 12-speed 1:1 technology ensures enhanced accuracy and response speed, while the enlarged bearing guide wheel allows compatibility with 52T flywheel for versatile cycling terrains.