Deep Throat Micrometer, 1" Range, 16" Reach, .0005" ResElectronic Thickness Gage with Mitutoyo Digital Indicator Deep Throat Thickness Gages are precision measuring tools used to measure the thickness of materials in hard to reach or confined areas. They are designed with an extended reach or "throat" that allows them to measure the thickness of materials in areas where traditional thickness gages cannot reach. This gage includes a 1" measuring range and a 16" deep reach, allowing you to measure thin