Quick Pressure QP-000040 Chrome Plated Brass 40 psi Tire Pressure Monitoring Valve Cap, (Pack of 4) TPMS alternative ALL GREEN: Properly inflated | PART RED/PART GREEN: Approximately 10% underinflated | ALL RED: Approximately 25% underinflated, ADD AIR ASAP NO Leakage, Breakage, Cross-threading, Shrinkage / Expansion, or Chemical Reaction (to valve stem) Patented, designed, assembled and tested in the USA After installation, DRIVE YOUR VEHICLE for 10 miles or more The tire rotation primes the pressure monitors to accurately display tire pressure status in the clear window No tool needed when installing Hand tighten only Save gas, save tires, safer drive Provide one year warranty