... Vacuum pressure compound Gauge,Vacuum Gauge,vacuum pressure gauge,Vaccum and compund Gauge,automoible gaugeDiameter: 1-1/2", 2", 2-1/2", 3", 4 ... steelWindow: acrylic, polycarbonateInternal: brass, stainless steelInlet thread: 1/8", 1/4", 3/8", 1/2", NPT ,BSPT, BSPConnection: bottom connection, center ... , Hg single or dual scale or according to customers order Vacuum pressure compound Gauge