These CF to Metal Tube adapter vacuum fittings follow Conflat standards. They have a flange sizes of Conflat 1.33. and a 0.250 in. tube. ConFlat (CF) flanges are used for ultra-high vacuum applications. These fittings can be used to introduce gas into a chamber. A valve could be attached to the entry point of the chamber for precise gas entry. These fittings use a copper gasket and knife-edge flanges to achieve the high vacuum seal and can operate down to 10-13 torr (10-11 Pa) and can be heated to 450 °C for bake-out. They have been Helium Leak Tested at 1x10-8 atm cc/second, and are UHV Rated. This line of Conflat fittings come in sizes CF-1.33, CF-2.75, and CF-3.375. These vacuum fittings are made of corrosive resistant stainless steel. ConflatŪ is a registered trademark of Varian Corporation.