This product is suitable for retrofit folding bikes, city bikes, and electric bikes. Lightweight with high axial strength and wide compatibility. Standard precision machining ensures chain retention, increases service life, and reduces friction. A reliable replacement for bike repair and upgrade, compatible with various bike models. 170mm crank arm length provides no overlap between crank arm and chainring. Specifications: 48T BCD double chainring x 170mm handle with square taper bottom bracket, includes 9/16-inch pedal axle, chain cover. Compatible with 6-speed and 7-speed rear derailleurs. Recommended for use with standard bicycle drivetrains. Color: Black. Material: Aluminum alloy. Package Contents: 1 x Crank Set. Note: Light and display differences may cause slight color variations between the image and the actual item. Measurement allows an error of +/- 1-3 cm.