For over 60 years, SPI has introduced innovative products to the metalworking and laboratory industries. SPI measuring instruments are durable, precise, and reliable — all backed by an industry-leading 2-year warranty. Easy-to-read 1-1/4" diameter dial has high-contrast markings. Universal positioning capability and jeweled bearing for flexibility and reliability. Balanced 0-15-0 dial for reading the difference from a specific surface reference point. Supplied with 3/8" dovetail stem, short form calibration certificate, and fitted case. Inch measuring standard: Minimum measurement: 0; Maximum measurement: 0.030"; Graduation: 0.0005".