... ",2.5",3",3.5",4",4.5",and 6"pressure range:-6...0 mbar up to 0...400 barsocket:heavy ... connection,bottom connection ,and clamp fixing,falaned fixing thread,hose etc.connection thread:NPT,BSP,BSPT,PT,ZG,and other special specification ... 55 degree centigrade;relative humidity below 80% dual scale diaphragm pressure gauge 0-30PSI