Milton, s-516W, Straight Foot Chuck Tire Inflator Gauge - Hose, Lock-On ThreadsFeatures:Performance-tested and calibrated. Measures in pounds per square inch (PSI, 10-160) and kilopascal (kPa, 80-840, increments of 2-lb.) readings.Makes tire valves more accessible with the two heads for easier access.One of the heads is parallel to the extension. Both heads have the feature to lock onto the threads, enabling the user to not have to hold the chuck while inflating. Easy one-hand inflation.Heavy-duty construction. Magnifying window lens. Full-swivel chuck. 15-inch hose.Gauge and valve cartridges can both be replaced.Milton specializes in tire inflator gauges were the very first in the industry to offer replacement cartridges! Gauge and valve cartridges are both replaceable. This essential pneumatic tool is ideal for any vehicle trunk, home garage, or automotive shop. Dual head chuck inflator gauge, where one of the heads is parallel to the extension. Both heads have the feature to lock onto the threads which enable the user to not have to hold the chuck while inflating. Made of heavy duty construction which provides for long life, even under extreme use and conditions. Equipped with magnifying lens for full view of scale. Full-swivel chuck.Auto, sport utility, truck, bicycle, motorsport, trailers, motor homes/5th wheels, wheelbarrows, golf carts, lawn tractors, motorcycles, ATVs, and more.If using a dual head type tire chuck with an inflator gauge and notice air is escaping through the off-side once connected to the tire's Schrader valve, simply release the trigger and remove the inflator from the Schrader/tire valve. Point the straight side of the outlet up into the air (make sure it's not pointed at someone). Squeeze trigger, allow air to flow (gravity will cause the sealing valve to drop), and place the chuck end onto the Schrader/tire valve while air is still flowing. Air will start to flow into the tire.Dual head type tire chucks are unable to inflate a completely flat (zero air pressure) tire. Tire air pressure would normally cause the sealing valve to move and seal the unused side of the chuck. However, if a tire has 0 air pressure, the self-sealing valve has no pressure to react to.