Accu-Glass flexible, open, single-flange Pyrex glass adapters are fitted with 321 stainless steel formed bellows. These glass-to-metal adapters are ideally suited for high and ultrahigh vacuum applications where vibration, expansion, contraction and/or misalignment compensation 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. Bellows and glass dimensions (overall lengths) can vary significantly from one assembly to another.