Standard Pack = 1 piece(s). Type = Digit Counter Disc Micrometer ; Range = 1 - 2 Inch ; Graduation = 0.0001 Inch ; Accuracy = 0.00016 Inch ; Flatness = 0.00004 Inch ; Parallelism = 0.00016 Inch ; Disc Diameter = 0.708 Inch ; Disc Edge Thickness = 0.035 Inch ; Center Opening = 0.280 Inch ; Features = Hammertone Blue Baked Enamel Finished Frame Is Tapered For Hard To Get At Places, Anvil And Spindle Are Hardened And Precision Ground With Microlap Finish On Measuring Faces, Positive Locking Nut On The Spindle, Quick And Easy Zero Adjustment On Sleeve, Ratchet Thimble, The Disc Type Anvil And Spindle Simplifies Measuring The Thickness Of Difficult, Closely Spaced Sections, Ribs, Keys, Fins, Cutting Edges On Forming Tools, Chordal Thickness Of Gear Teeth, Etc, Meets Or Exceeds Federal Accuracy Specs, Sizes Over 1 Inch Include Standards ;