Tire pressure monitoring plugs are an easy way to check tire pressure. With a simple traffic light color system, you can quickly see if tire pressure needs to be changed. . Material: Made of chrome metal and PC. . 3 Color Monitor: Green, yellow and red system indicates tire inflation level. According to the recognition color to display the tire pressure: Green indicates that the tire pressure is normal Yellow shows that the pressure is 10% lower than the standard Red indicates that the pressure is 25% lower than the standard. . Safety: Car tire pressure monitoring valve caps visually alert you when tire pressure is low. Helps avoid premature tire wear or under-inflated tire failure, increases fuel efficiency, safety and fuel control, extends tire life. . Widely Used: Suitable for car, motorcycle, bicycle and so on. Suitable for 3236PSI (2.22.4Bar). .