15 x 45 mm, 1 dram (4 ml) Amber borosilicate glass vial with 13-425 black phenolic polyseal™ cone lined cap attached. Amber screw thread vials offer protection from harmful light and uv rays for light sensitive products. these general purpose glass vials are made of type i borosilicate glass, providing exceptional resistance to heat shock and chemical leaching. Attached black phenolic (thermoset) caps with polycone liners form an exceptionally tight seal and offer a good chemical barrier. This liner molds itself around the sealing areas of the finish as the cap is screwed on, virtually eliminating leakage, evaporation, contamination, binding and backing off. Great for everything from liquids, to soaps, to macro-invertebrates.