Ascot N 1410 OTR Tire Tread Depth Gauge with Window Industrial Tubes lbs of max torque in ASC395 20070 lbs of max torque in reverse position for high productivityMetal housing and rocking dog impact mechanism for high durability and smooth operationConvenient reverse valve and teasing trigger for better comfort in useEasy to useConvenient reverse valve for easy directional changesFeatures Do not measure center to center across the hub Aluminum OTR Tire Tread Depth Gauges indicating bar is calibrated in 32nds on one side and millimeters on the other and hit has a magnified sight glass for easily reading the measurements Measures tread depth up to 6 inches