Detailed Product Description Freon Gauge Diameter: 2-1/2", 2-3/4", 3", 4"Case: plastic, steel, stainless steelWindow: glass, acrylic, polycarbonate Internal: brass, brass with dampInlet thread: 1/8", 1/4", 3/8", 1/2", NPT ,BSPT, BSPConnection: bottom connection, center back male connectionRange: 1~17kg/psi,0-35kg/cm2 or according to customer orderScale: psi, bar, Mpa, Kpa, kg/cm2, Hg single or ...