Fowler Mechanical Deep Throat Micrometer Features Include... 0-1" / 25mm Measuring Range 0.0001" Graduations + 0.00016" Accuracy 6" Deep Throat Flat Carbide Tipped Faces on Anvil & Spindle Enamel finish frame. Ratchet Stop. Spindle Lock For sheet metal and similar applications Spindle diameter: 0.256" Furnished in fitted case