Fowler's 0-.4" Dial Indicator with 0.0005" Graduations Fowler's Coolant Proof Dial Indicator includes a rubber bellows on stem, O-ring seal on safety cap, O-ring protection for bezel and rotating dial, and a sealed back plate. Specifications include... .40" Travel 0.0005" Graduations 0-50-0 Face Reading 2.25" Dial Diameter Revolution Counter Lug Back Carbide Point M2.5 Threaded Carbide Point Features include... Revolution counter hand. Supplied with lug backs positioned through 90° increments. Spindle rack & contact points of hardened stainless steel for long wear; cases forged brass, satin-chromed; gear wheels hard brass. Pinions of silver steel, hardened tempered and burnished on pivots; lapped on teeth. Microfine graduations in black for continuous readings and red for balanced readings.Available in metric graduations. Movement mounted independently from case on rigid supporting plate, ensuring perfect and permanent alignment. Extra long springs for uniform pressure through entire travel of spindle.Bezel knurled; easily adjusted thru 360å¡. Meets AGD specifications. Group II & III gages measuring pressure approximately 2 oz. except .0001" (.002mm) which is 5 oz. Includes adjustable tolerance limit markers.