Features. Aijiren 12 mm vial racks are ideal for holding 2 mL glass vials ( 2 ml screw vials, 2 mL crimp vials or 2 mL snap vials) for table top sample prep. Vial storage boxes are able to hold 50 x 2 mL vials instead which offer a cover when compared to an open vial rack. Return to top.