Custom Auto, Mini Double Ring Tire Pressure Gauge - 50 PSI, A mini tire pressure gauge and key ring all in one! This versatile, compact product helps you keep your tires properly inflated, which can improve gas mileage. The pressure gauge measures up to 50 PSI. Ideal for auto industry Measures up to 50 PSI Improve gas mileage by keeping tires properly inflated ... #21110 $2.00/each.