The set of 4 - 100 PSI Crossfire Tire Equalizer valves by Dual Dynamics for tires with a normal tire pressure setting of 100 PSI. These tire pressure valves assist in decreasing rolling resistance for increased fuel mileage while improving stability, braking and overall safety. These valves install in minutes, require little maintenance including cutting maintenance time due to a single-point inflation and visual pressure gauge. Crossfire is a pressure equalizing and monitoring valve that is mounted between dual tires. It bolts easily to the lug, Hubcap, or drive axle end. When you properly mount this valve, air freely flows from one tire to the other, maintaining equal tire pressure and load distribution.