This product is suitable for retrofit folding bikes, city bikes, and electric bikes. Features high axial strength and wide compatibility. Precision machined to standard specifications, ensuring chain retention, extended service life, and reduced friction. A reliable replacement option for bicycle repair and upgrades, compatible with various bike models. 170mm crank arm length designed to prevent overlap with chainring bolts. Specifications: 48T double chainring, 170mm crank arm with square taper bottom bracket, includes 9/16-inch pedal axle and chain guard. Compatible with 6-speed and 7-speed drivetrains. Installation suitable for common bicycle frame types. Color: Black. Material: Aluminum alloy. Package Contents: 1 x Crank Set. Note: Other items not included. Due to lighting and display differences, the actual color may vary slightly from the image. Measurement tolerance: +/- 1-3 cm.