Package Includes: One pack of left-arm crankset included. The orientation of this left crank arm features a rhombic hole (slanted hole). Please check the product description carefully to ensure compatibility with your bike. About Size: 170mm crank arm length with no overlap of the crank arm and chainring bolt. This bike crank arm helps ensure chain retention, increases service life, and reduces friction and noise. High Quality: Made of premium aluminum alloy, lightweight, with high axial strength and durability for long-term use. Easy to Install: Standard precision cutting of the hole ensures a proper fit for the bike. Smooth finish with durable paint coating for a stylish appearance. Multiple Function: Crank arms are coated to enhance scratch resistance and provide a textured matte black finish. Suitable for road bikes, mountain bikes, folding bikes, fixed gear bicycles, and more. Color: Black