1.Material:Brass and Nylon 2.Negative pressure can be up to 635mmHg 3.Many joints and tubes ... ,rubber piston ring and valves.4.Precise pressure gauge:0-30inHg,0-760mmHg.5.Negative pressure up to 635mmHg.6.Release valve ... ,leak tests,experiments,vacuum packaging and so on. Brass,negative pressure, auto repair testing tools & hand vacuum pump,TS8003