Functionality: They serve primarily as a safety and aesthetic accessory for vehicles. The glowing effect helps make your car more visible in the dark, potentially increasing safety, especially in low-visibility conditions.

Design: The caps are usually designed to replace standard tire valve caps. They are often made of durable materials to withstand various weather conditions and the rigors of driving.

Installation: Installation is typically straightforward and requires no special tools. You simply screw them onto the valve stems of your car tires.

Variety: They come in various designs and colors, allowing car owners to choose options that match their vehicle's style or personal preferences.

Power Source: Some models may use replaceable batteries, while others might have built-in rechargeable batteries that are charged via solar power or induction from the rotation of the tires.

Usage: While primarily decorative, they can also provide a subtle light source that makes it easier to find your tire valves at night.

Considerations: It's essential to ensure that any modifications to your vehicle comply with local regulations and do not interfere with the safe operation of your car.