SPI 0" to 6" Range, 0.001" and 0.02 mm Graduation, 0.001" per Revolution, Dial Caliper White Face, 40mm Jaw Length, Accurate to 0.02mm, NIST Traceability Certificate Dual graduated dial face for inch (0.001" graduations in black) and metric (0.01mm in red) Shockproof design and precision ground stainless steel construction with 1.57" jaw length 4-way measurements: inside, outside, depth, and step Thumb wheel and slide lock 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.