Specification:Features: high quality Nylon PA66 material, in use. Exquisite appearance, sturdy, and dustproof. Professional manufacturing, high reliability.Easy and convenient to install.Anti-theft , high-end, fashion, materials, delicate craftsmanship. Suitable 21mm screws (car Wheel hub).Specifications:Condition: Material: Nylon PA66Color: Black Gray Red Yellow (optional)Front size: 25.8mmReverse inner diameter: 21mm,Side height: 24.5mm low root size: 17.2mm Package Weight: Approx.88g/3.1ozFitment: for 21mm wheel screwsPackage List:20 * Hub cover 1 * Nylon clip