• It is made of high-tensile chromium-molybdenum steel, with nickel-plating surface, so it has higher strength, durability and has extreme resistance to abrasion. The strong antioxidation makes it hard to rust to have a long service life
• The hollow design can reduce the weight to some extent and make riding easier
• Use it to directly replace your old or broken flywheel
• A wonderful accessory for mountain bikes. Easy to install

Specification:

• Teeth ratio: 11-13-16-20-24-28-32-36-42T
• Material: chromium-molybdenum steel (nickel-plating surface)
• Speed: 9 speed