These aijiren Tech™ National™ 10mm Wide Opening Screw Thread Vials and Inserts are manufactured from clear, (Type 1 Class A) glass and have a 10-425 thread finish. The wide neck opening design allows easy filling requires micro-Inserts with a diameter of 6mm. Product Size. Pack of 100. Type. Unassembled Vial Kit. Vial Closure Size. 9