Features: 1Aluminum Alloy Body: The main body is forged with aluminum alloy, the strength is unchanged at the same time of light weight, and the surface layer is painted with anti rust treatment. 2Carbon Steel Chain Guide: The chain guide is made of carbon steel, with hardened surface oxidation treatment, high rigidity, wear resistant and rust proof, durable and long service life. 3H/L Adjusting Screw: H/L is the positioning screw. The two screws are adjusted to ensure that the chain is between the largest and smallest pieces of the flywheel. H is the high position and L is the low position. 4Assembly Usage Example: The shifting cable pulls the chain guide to move the chain, making the chain runs on different gears of the chainring, and realizing the transmission gear ratio of different speeds, so that the riding is more labor saving and faster. 5Installation Diameter: Delivery of 30.8mm/1.2in, 31.8mm/1.3in conversion clamp ring, support 30.8mm/1.2in, 31.8mm/1.3in, 34.9mm/1.4in pipe diameter, general mountain bike can be used universally, according to the actual situation of the vehicle. Package included: 1 x Front Derailleur&nbsp 1 x Conversion Clamp Ring