Accu-Glass domed, single-flange glass adapters are offered in 7052 Borosilicate or 7740 Pyrex glass. They are fitted with low-expansion Nickel-Iron (Kovar®), and stainless steel metal transitions respectively. These closed end adapters are ideally suited for high and ultrahigh vacuum applications where an optically clear glass chamber 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 mounting flange dimensions) all dimensions are nominal, and for reference only. Glass dimensions (overall lengths) can vary significantly from one assembly to another.