Kimble 60940D-12 Borosilicate Glass Cylindrical 2mL Sample Vial, with Rubber Lined Closure Unattached (Pack of 144) Economical and saves time in the lab Vial top has a screw thread finish Composed of KIMAX KG-33 borosilicate glass; meets the requirements for ASTM Type 1, Class A and USP Type 1 Glass and combines a low coefficient of expansion with a very high chemical resistance Cylindrical shape provides solid balance Flat bottom facilitates free-standing capability