Vials are made of Wheaton 33® clear or Wheaton 320 amber low extractable borosilicate glass.

Especially suited for research studies where stability of the glass is of prime importance. Vials are autoclavable. White polypropylene open-top caps have a specially designed septum of 5 mil of fluoropolymer resin facing 0.12 mil of silicone. The white polypropylene is glass-filled to provide extra chemical and heat resistance compared to standard polypropylene. The fluoropolymer resin-faced silicone septum is bonded to the cap, providing a permanent connection.