1、O‑ring is made of aluminum alloy to assure durability, heat resistance, oil resistance, and corrosion resistance. 2、The O‑ring is about 2 mm thick, the outer diameter is about 39.8 mm, and the inner diameter is about 34.9 mm. It is lightweight, easy to install and remove, and easy to use. 3、Suitable for adjusting the chassis, steering wheel or bicycle hub, the gasket will not accumulate dust or oxidation. 4、Different color settings meet your different needs, ensuring that your bike is full of appeal. 5、Can be applied to BB axle. The package contains 15 O‑rings, which provide you with an economical replacement, suitable for various applications, enough for your daily use and replacement. Condition: 100% Brand New Item Type: Bicycle Washer Material: Ultra-Light Aluminum Alloy Quantity: 1 Set (15pcs) Process: CNC+ Surface Anode Inner Diameter: Approx. 34.9mm / 1.4in Outer Diameter: Approx. 39.8mm / 1.6in Thickness: Approx. 2.5mm / 0.1inOptional Color: Red, Black Purpose: The gasket is used for the bottom bracket Purpose: The 8-speed hub is installed with a 7-speed chuck-type flywheel, and a washer is required, or a washer can be added to the extended bottom bracket. It is also suitable for BB bottom bracket. 1 x Set of Bicycle Washer(15pcs) Hub Problem: 1. When you are loading the car, do you encounter the situation that the flywheel is too loose on the hub? 2. When you are loading a car, do you encounter an eight-speed flywheel hub installed with an eight-speed flywheel? 3. When you want to install a single-speed car. The Problem with the Bottom Bracket: 1. When you are loading the car, do you encounter the situation that the chainring disc hits the frame? 2. When you are loading the car, do you encounter the situation that the crank of the chainring hits the frame? 3. When you are loading the car, do you encounter the problem that the minimum gear cannot be lowered? 1 x Set of Bicycle Washer(15pcs)