Luminous Design: Glow in the dark, when the wheel starts to move, it will automatically flash and produce a circle of light, making your car the coolest and most eye-catching in the dark Excellent Air Tightness: The illuminated stem cover is made of high quality ABS material and has a rubber seal valve cover to form a more effective seal, so it won’t leak during long driving Protect car tires: Luminous tire air caps can protect the valve and prevent water, dust or sand from entering the tire; prevent valve leakage and ensure safe driving Easy installation: No tools required, just screw the cap onto the tire valve stem to install. Rotating threads on car tire air caps to facilitate twisting during installation or removal Universal Size: Tire valve cover for bicycles, cars, SUVs, motorcycles, trucks and other motor vehicles