This item are auxiliary tools for measuring car tire pressure, durable and sturdy, which can be used for long time. They can road handling and extend the lifespan of tire. Green, yellow, red color indicates level of proper tire inflation. With stable working performance, it increases fuel efficiency, safety and control of your car tire. Features - ColorAssorted Color - Material: copper, PC, stainless steel. - Size: 2.50X1.00X1.00cm/ 0.98X0.39X0.39inch. - Adoption of copper, PC and stainless steel material, these tire pressure monitoring caps are durable and sturdy. - With stable working performance, it increases fuel efficiency, safety and control of your car tire. - workmanship, and anti-theft functions, can road handling and extend tire life. - Green, yellow, red color indicates level of proper tire inflation, and increases fuel efficiency. - Increase the anti-theft nut design, safe and secure, the tire pressure caps is not easy to be taken by others. Cautions: Normal: Under the condition of standard tire pressure, the transparent +A15: window should be green, and the vehicle is running normally Warning: The tire pressure is slightly lower than the about 10%, the transparent window is yellow-green, and it should be inflated in time. : The tire pressure is lower than the about 25%, the transparent window should be yellow, and it should be checked and inflated immediately. Package list: 8 Tire Pressure Monitor Caps 8 x Screw Nuts 1 x Spanner