... ",2.5",3",4",6". Bottom Brass Connection Stainless Steel Oil Filled Pressure Gauge 1. Diameter: 1 ½", 2", 2 ½ ",3",4",6";2.Case ... according to customers order.9.Oil composing:glyceine, silicone oil;10.Accuracy: 2.5%,1.6%,1%. Bottom Brass Connection Stainless Steel Oil Filled Pressure Gauge