Target 2mL Screw Thread vials have a wide neck that accommodates a 10mm cap (10-425 mm thread). Vial is 12 x 32mm size. Made of superior quality 33 expansion borosilicate glass (Type 1, Class A). Uniformly flat bottom for security with inserts. I-D vial has a write-on patch with graduations at 0.5, 1.0 and 1.5 mL.