Cap Material is black phenolic and cap and liners are autoclavable. This sample vial and closure combination provides an extremely inert and chemically resistant environment for harsh, sensitive and reactive samples. The Shorty vial features a low profile for greater stability and less dead volume above the sample, making it suitable for compound storage. Vials are packed in the Lab File format of corrugated trays with partitions and shrink wrapped to reduce particulate contamination. They are manufactured from Wheaton 33 low extractable borosilicate glass, which meets ASTM Type I Class and USP Type I standards.