Product Description 045 Magnehelic pressure gauge Size: 2.5" or 4" Pressure Range: From 30niHg to 1600bar Socket: 304 St St ,316 ST St material Thread: BSP,NPT BSPT,PT,ZG,and other special specification Bourdom Tube: 316 stainless Steel material Highe Case: 304 St St bayone ring or 316... https://www.hongqiinstrument.com/pressure-gauge/pressure-gauge-for-certain-gases/045-magnehelic-pressure-gauge.html