Description: Fluorescent Effect: The inner layer of the valve stem cover designed with luminescent material, and fluorescent is added. It must first absorb all kinds of visible light energy and store the light energy before it can automatically in the dark and can be recycled unlimited times. Test: To test whether there is a fluorescence effect, first irradiate the flashlight with strong light for five minutes. The fluorescent effect can be seen in a place where there is . This can be reused. The longer the light is absorbed, the longer the light is emitted. Double Protection: The tire valve cap can protect the tire valve from dust and prolong the service life of the tire. Material: The valve cap is made of high quality material. Texture design is master and use. Easy To Install: Universal tire valve caps be easily installed without tools. screw it onto the tire valve stem. When you want to check the air pressure, it is easy to install or remove. Specification: Material:PP Size Chart: 1.6cmx1.2cm/0.63inchx0.47inch (Inner diameter 8mm) Package Includes: 1 Tyre Valve Stem Caps(4 Pack) Note: Please allow slightly errors due to manual measurement and different monitors.