20 ml (5 dram) Amber glass vials, black vinyl lined caps. Amber vials offer protection from harmful light and uv rays for light sensitive products. Made of type i borosilicate glass, providing exceptional resistance to heat shock and chemical leaching. The glass is non-porous and has no catalytic affect. Because the boron oxide particles in the glass are so small, the silicate is held more closely together, resulting in a much stronger glass for your laboratory needs. Attached 24-400 black phenolic caps with pulp and vinyl liners are perfect for general use. The liner is made of a vinyl coating applied to high density polyethylene coated paper and then it is laminated to pulpboard. This general purpose liner is commonly used for food, beverage, medical and chemical applications packed at less than 120 deg F.