Premium Material:This bike belt drive plate is made of safe and sturdy PP material, with high stability and strength, and reliable performance Easy to Replace: The exercise bike tension belt disc is easy to install and use Replacement Accessories: This dynamic bike belt wheel disc is made of quality PP material and can withstand high intensity training. It is a necessary accessory for indoor cycling enthusiasts Smooth and Efficient: The fitness bike part adopts a belt drive design to ensure smooth and efficient operation during exercise Function:Fitness stationary bike belt drive disc is great for enhancing your indoor cycling or fitness experience Specification: Material: PP Iron Size Chart:Outer Diameter: 18cm/7.09inch Hexagonal Shaft Available:1.7cm/0.67inch 2cm/0.79inch Package Includes: 1 Exercise Bikes Drive Belt Disc Note: Please allow slightly errors due to manual measurement and different monitors.