and Features: Premium Material: The mountain bike crank is made of aluminium alloy material, which is high-strength and light-weught, preservative and wear-resistance, it is durable to use, can maintain a long service life. High Strength: This bike crank has strong axial strength and strong compatibility, which is A good accessory for remodeling mountain bike. Appearance: Our crank adopted lightweight and compact appearance, it can make your car more attractive. Narrow Wide Sprockets: The narrow wide tooth design, increasing the contact area with the chain greatly, so that each of the teeth can be fully inserted into the chain, increase the grasp force, make you no longer worried about the chain dropped, easy to pass through the bumpy road. Through the modification single speed chain rings, reduced the transmission system greatly, completely abandoned the complex variable speed system,reduce the bike weight, looks more compact and simple, and also greatly improve your speed. Easy to use and to operate. Road Bike Chainwheel and Crank only,other accessories demo in the picture is not included. Specification: Material: Aluminum Alloy Optional Crank Length: 01, 02 01 Crank Length: app.17cm/6.79in 02 Crank Length: app.17.25cm/6.79in BCD Size: app.13cm/5.12in Color: Black Quantity: 1 Set Note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Contents: 1 x Road Bike Chainwheel 1 x Crank Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.