1. HIGH ACCURACY: Bike flywheel gears use high accuracy thread machining to ensure a tight connection to the bike hub and stable running. 2. LOW NOISE: Bike freewheel cog provides fast riding speed while saving effort, fluent turning action without much noise. 3. STEEL MATERIAL: Bicycle flywheel gears are made of steel, strong and durable, anti corrosion, not easy to damage, long service life. 4. EASY TO INSTALL: Replacement freewheel gears are lightweight and compact, and can be easily disassembled or mounted on the bike. 5. BICYCLE ACCESSORIES: Road bike freewheel cog is and suitable for mountain bike flywheel, a good accessory for bicycle. Spec: Item Type: Bike Flywheel Gears Material: Steel Speed: 12 Speed Package List: 1 xBike Flywheel GearsSTEEL MATERIAL: Bicycle flywheel gears are made of steel, strong and durable, anti corrosion, not easy to damage, long service life. LOW NOISE: Bike freewheel cog provides fast riding speed while saving effort, fluent turning action without much noise. HIGH ACCURACY: Bike flywheel gears use high accuracy thread machining to ensure a tight connection to the bike hub and stable running. EASY TO INSTALL: Replacement freewheel gears are lightweight and compact, and can be easily disassembled or mounted on the bike. BICYCLE ACCESSORIES: Road bike freewheel cog is and suitable for mountain bike flywheel, a good accessory for bicycle.