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, extends service life, and reduces friction. A reliable replacement for bike repair and upgrade, compatible with various bike models. Features a 170mm crank arm length designed to prevent overlap between the crank arm and chainring. Specifications: 48T BCD double chainring x 170mm crank arm with square taper bottom bracket, includes 9/16-inch pedal axle, and chain cover. Compatibility: Designed for use with 6-speed and 7-speed drivetrains. Color: Black Material: Aluminum alloy Package Contents: 1 x Crank Set Note: The package includes only the items listed above. Other accessories are not included. Due to lighting and display differences, the actual color may vary slightly from the image. Measurement tolerance is +/- 1-3 cm.