Item Type: Luminous Tire Valve Cover Material: Rubber Inner Diameter: Approx. 8mm / 0.31in ( Manual Measurement, Slight Error May Exist ) Outer Diameter: Approx. 12mm / 0.47in ( Manual Measurement, Slight Error May Exist ) Height: Approx. 16mm / 0.63in ( Manual Measurement, Slight Error May Exist ) Weight: Approx. 10g / 0.35oz Package List 4 x Luminous Tire Valve Cover 1Glowing in Dark: These luminous tire valve covers absorbs the energy of various kinds of visible light (such as lamps, the sun, etc.) and stores the energy of light, and then glowing in the dark. 2Durable Rubber: These luminous wheel valve stems are made of premium rubber material, strong and durable. 34 Pieces: You will receive 4 pieces of luminous tire valve stems in total, meeting your basic needs for the car. 4Light Weight: These glowing tire valve covers are light and resistant to corrosion and water, easy to carry. 5Easy Installation: These fluorescent tire valve covers can be easily installed, saving your time and effort.