These Sample-Seal U-tube liquid sample holders are used to store precursors that generate vapors to be flowed into the vacuum chamber. These U-tube liquid sample holders include two 0 to 4 mm adjustable high-vacuum valves which produce a leak-tight o-ring seal. They are designed with 0.625 inch OD on the glass straight sections before the U-shape and include inlet and exhaust ports of ¼ inch outer diameter glass connections. These U tube liquid sample holders are designed to withstand pressurizing up to 50 PSI and are often used in molecular spectroscopy experiment to contain the precursor liquid samples before the spectrometer. They are about 10 inch long, 2 inches wide (outside edge of glass u-shape), with 1/4 OD glass connection and are often connected to flexible Swagelok tubing by Ultra-Torr compression vacuum fittings. Replacement o-rings are sold separately, please call 505-872-0037 for more information.