This Easy To Use Tire Gauge Is Small Enough To Fit In The Glove Box, Yet Delivers Like A Much Larger Unit! Knowing The Correct Pressure On Your Tires Will Increase Fuel Efficiency And Improve Vehicle Handling 5 - 60 Psi. May Require Adapter To Fit Your Tire (not Included). Turns On Automatically When Pressure Flow In, And Turns Off When Not In Use.