Description: Car Tire Pressure Monitor Valve Stem Caps: A simple way to check tire pressure. You can fastly confirm if the tire pressure needs to be modified. Made of high-quality pure copper core, not easy to rust, stable, durable and practical. Three-Color Monitor: Display proper car tire pressure according to recognized color. The transparent window shows green means tire pressure is normal; Yellow green means pressure is 10% lower than standard, should be inflated in time; red yellow reminds your car tire pressure is 25% lower than standard, check and inflate immediately. Design: Air Remind Tire Valve Caps come with metal shell that prevents the valve stem from corrosion. Easy to Use: With rotating thread makes Valve Stem Caps easy to twist while installing or removing. Wide Application: The valve caps are suitable for most cars, motorcycles, bicycles, SUVs, trucks, etc. Specification: As Your Choice: Brass Core Brass Shell OR Brass Core Stainless Steel Shell Size Chart: 0.9cmx2.3cm/0.35inchx0.91inch Package Includes: 4 Tire Pressure Indicator Valve Stem Caps 4x Nuts 1 Wrench(4 Pack) Note: Please allow slightly errors due to manual measurement and different monitors.