This product is suitable for retrofit folding bikes, city bikes, and electric bikes. Supports variable speed freewheel with high axial strength and compatibility. Features standard precision machining for chain retention, increased service life, and reduced friction. A reliable replacement for bike repair and upgrade, compatible with various bike models. 170mm crank arm length with no overlap between crank arm and chainring bolt. Color: silver. Material: aluminum alloy. Package includes: 1 x chainring with crank, 1 x crank. The package includes only the items listed; other products are not included. Note: Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1-3 cm.