Detailed Product Description pressure gauges decription:Case sizes: 1.5", 2", 2.5", 3" and 4" Case metarial: black ... micrometerConnection: 1/8", 1/4", 3/8",1/2", BSP, NPT or BSPT M14X1.5 M10 X1 ... window Accuracy: ASME B40.1 Grade B (3-2-3%) Options and accessories: custom dial, metric scale ... , DIN 2.5% accuracy, restrictors, special connections and more ...