Brand Features: Premium Material: The mountain bike crank is made of high-quality aluminum alloy material, which is high-strength and lightweight, corrosion-resistant and wear-resistant, durable for long-term use with extended service life. High Strength: This bike crank offers strong axial strength and broad compatibility, making it a reliable accessory for mountain bike upgrades. Design: The crank features a lightweight and compact design, enhancing the overall look of your bicycle. Narrow Wide Chainrings: The narrow-wide tooth design increases the contact area with the chain, allowing each tooth to fully engage the chain links, improving grip and reducing the risk of chain drop, especially on rough terrain. Single-Speed Conversion: By converting to single-speed chainrings, the drivetrain is simplified, eliminating the complexity of multi-speed systems, reducing overall bike weight, creating a cleaner appearance, and potentially improving efficiency. Easy to install and operate. Road bike chainwheel and crank set only; other accessories shown in images are not included.Specifications: Material: Aluminum Alloy Crank Length Options: - Option 1: Approximately 17 cm / 6.7 inches - Option 2: Approximately 17.25 cm / 6.8 inches BCD Size: Approximately 13 cm / 5.1 inches Color: Black Quantity: 1 SetNotes: No retail packaging included. Please allow 01 cm variation due to manual measurement. Ensure you are comfortable with this before purchasing. Due to differences in monitor displays, actual color may vary slightly from the image.Package Contents: 1 x Road Bike Chainwheel 1 x Crank