Legacy Manufacturing Gas Saver Tire Valve Cap, Low Air Pressure Indicating (36 PSI) - TH0402 GREEN PSI INDICATOR - The green indicator inside the Gas Saver valve cap activates at 31 psi or below, indicating a low pressure tire condition PSI TIRE RATING - Rated for 36 psi tires MAXIMIZE TIRE AND CAR PERFORAMNCE - Maintaining the proper tire pressure will maximize the performance and life of tires. It also improves vehicle handling and helps prevent blowouts MAXIMIZE GAS MILEAGE - Properly inflated tires will increase gas mileage