This is the Shimano Altus M371 9 Speed Conventional Swing Front Derailleur & is a wide link 9-speed compatible dual pull multi-fit front derailleur for recreational off-road use. The conventional swing gives a positive shifting action, while the dual pull design allows it to be used with top or bottom cable routing. The multi fit clamp means you can use it on any size sear tube. Best used on mountain bikes with 66-69 degree chainstays to seat tube angle range, with the a outer chainring size of between 44 & 48 teeth.