Material and weight: Steel has strong wear resistance and durability. The weight of the 12-speed 11-28T is about 218g Hollow design: Hollow design reduces a lot of weight and reduces the burden of long-term riding. The high-precision thread ensures tight connection with the bicycle hub and smooth operation. Note: This product is a 12-speed 11-28T silver, (please confirm whether your bicycle meets the installation requirements before purchasing, and confirm that the ordered product is correct). Easy to Install: The Freewheel Replacement Accessorycan directly replace your old or broken Freewheel, Wonderful accessory for mountain bike and Road cycling. Features: Has higher strength, fine durability and has extreme resistance to abrasion. Easy to control the shift function, due to the special design of the gear sprocket exclusively for mountain bike. The strong antioxidation makes it hard to rust to have a long service life. A fine appearance and will give you a luxurious feel. Brand: SWTXO Model: road bike ultra light flywheel Material: Chrome Molybdenum Steel (Surface Nickel Plated) Speed: 12 speed Color: Silver Packing: Bulk (OPP bag) Compatible with 12-speed HG system for road bikes Teeth and weight (ultralight version): 12-28 T: 11-12-13-14-15-16-17-19-21-23-25-28T about 223g Applicable to: 12-speed, compatible with SHIMAN0 105 5800 ULTEGRA 6800 6870 R7000R8000 and 11-speed road kits such as Superlink, Suntech sensah, LTWOO blueprint, micro-shift microshift (note that it must be a conventional cassette hub freehub)