1、Light Weight and High Strength Main Body: The main body is forged with aluminum alloy for light weight and high strength. The surface layer is painted with anti rust treatment, which is more durable. 2、Carbon Steel Guide Chain Piece: The guide chain piece is made of carbon steel, with hardened surface oxidation treatment, it has high rigidity, and is wear resistant and rust proof, and durable. 3、H/L Adjustment Screws: H/L height adjustment screws, high compatibility two way pull type arm (both pull up and pull down wiring support, good compatibility), accurate and direct power transmission, quick and sensitive speed change. Accurately adjust the positioning screw to adjust the derailleur to the best working condition. H/L is a positioning screw. The adjustment of these two screws is to ensure that the chain is between the largest and smallest flywheel. H is the high position and L is the low position. 4、Labor Saving and Faster Riding: The shifting cable pulls the chain guide to move the chain, so that the chain runs on different gears of the chainring, and realizes the transmission gear ratio of different speeds, so that the riding is more labor saving and faster. 5、30.8/31.8mm Clamp Ring: With 30.8/31.8mm conversion clamp ring, support 30.8/31.8/34.9mm pipe diameter, most mountain bike can be used, and it needs to be used according to the actual situation of the bike. Item Type: Bike Front Derailleur Material: Aluminum Alloy Body + Carbon Steel Chain Guide Product Color: As Pictures Shown Product Weight: Approx. 165g / 5.8oz Applicable Speed: 3 x 9/10 Speed Installation Diameter: 30.8mm / 1.2in, 31.8mm / 1.3in, 34.9mm / 1.4in Applicable Crankset: Three piece crankset with 42, 32, 22 Teeth Applicable Models: Suitable for mountain bike and folding bike Installation Method: Conventional Clamp On Installation (with Clamp Ring) 1 x Bike Front Derailleur 1 x Clamp Ring Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.