This Kontes NMR tube with an attached cap is 100% gauged to meet the most exacting standards. It is designed for use in high-resolution NMR spectroscopy that characterizes organic molecules through measurement of the resonant frequencies of atomic nuclei. Research applications include analysis of polymer structures and organic solutions. Tube comes with plastic compression-fit cap and has sandblasted marking spots. This tube is ideal for sealing directly to vacuum manifolds, joints or valves.