KIMAX bottles are graduated with an approximate capacity scale. Bottom outlet is controlled with an 8 mm valve which can be used with 1/4" flexible tubing (not supplied) attached to the quick release hose barb connector. It may also be used with rigid 1/4" O.D. PTFE tubing with the o-ring and cap supplied on the quick release connector. Glass conforms to ASTM E438, Type I, Class A.