Magnetic dual-flange glass adapters are offered in Corning 7052 (or equivalent) Borosilicate glass tube. They are fitted with expansion-matched Nickel-Iron-Cobalt (Kovar), metal transition tubes. These flanged adapters are ideally suited for high and ultrahigh vacuum applications where electrical break and/or isolation between components is required. Available in four (4) glass tube sizes including 1/2, 3/4, 1-1/2 and 2-1/2 inch diameters. NOTE that glass-to-metal sealing is more of an art than a science, and as such (other than tube and mounting flange dimensions) glass dimensions are nominal, and only for reference. Glass lengths can vary significantly from one assembly to another.