Slime S20221 Tire Pressure Valve Cap, 32 PSI (4-Piece Set)

Slime Tire Pressure Valve Caps are designed to give drivers an early warning when their tire pressure drops below the recommended pressure. Caps come in 32 PSI and 36 PSI versions. When the pressure in the tire is normal, a green ring is visible around the top of the cap. As the pressure begins to fall, the green ring becomes smaller. If no green ring is visible, the tire pressure should be checked immediately.