The Chorus 12 speed cassette features the same performance a features of the higher tier record and super record derailleurs in more affordable materials 3D Embrace technology and 12-teeth pulley wheels makes this rear derailleur suitable for all cassettes as the distance stays optimum on each individual sprocket, regardless of the cassette selected On rough roads, the spring positioned between the upper body and the pivot absorbs the vibrations, ensuring the chain always rests properly on the sprockets Initial position of the rear derailleur can be adjusted to suit any cassette The rear derailleur is positioned further back, making it easier to slide the wheel out and replace it RD20-CH12 12sp 32 Mid 1to1 BLK Chorus 12-speed UPC/EAN/GTIN: 8053340453519