10-751-6 SPI Hole Mike 4.00" - 5.00"SPI Hole Mike 3 Point Internal Micrometer Specifications Include 4. 00" 5. 00" Measuring Range 0. 0002" Readings 5. 51" Measuring Depth Includes Case Setting Ring NOT included Features include Three point internal micrometer for precise, direct measurement of bore diameters. Self aligning and self centering Carbide measuring anvils Suitable to measure to within . 050" of bottom of blind hole, up to 4" capacity Feelers taper toward the back for