Check the listing for details. SPI 12-401-6 Internal Dial Caliper Gauge: 0.375-1.375" Range, 0.001" Graduation. Condition: New. Listed at 116.12 USD. The SPI 12-401-6 internal dial caliper gauge checks internal bores and recess diameters within a range of 3/8 inch to 1-3/8 inch. Graduated to 0.001" with 0.0015" accuracy for reliable measurements. Legs are 3.25 inches long with 0.06 inch diameter ball contact points. Premium construction with black oxide finish caliper arms and chrome-plated housing and bezel. This gauge excels at measuring hard-to-get-to internal diameters within a one-inch movement range. Can be set with a micrometer or ring gauge. The bezel rotates for zero setting, and there is a button for closing the arms. Arms automatically open when button is released. The caliper is spring loaded to make point contact at a constant measuring pressure.