... .5",2",2.5",3",4",6". Bottom Brass Connection Stainless Steel Oil Filled Pressure Gauge 1. Diameter: 1 ½", 2", 2 ½ ",3",4",6 ... ", 3/8",1/2",NPT,BSPT,BSP;6.Connection: bottom connection, center back male connection;7.Range:0~10,000psi;8.Scale:psi,bar ... oil;10.Accuracy: 2.5%,1.6%,1%. Bottom Brass Connection Stainless Steel Oil Filled Pressure Gauge