5188-2788 - Vials, 0.3mL PP 100/PK. Vial, crimp/snap top, polypropylene, certified, 250 µL, 100/pk. Vial size: 12 x 32 mm (11 mm cap) Manufactured from virgin polypropylene, meeting requirements of 21 CFR 177.1520. Aijiren 12 x 32 mm wide opening vials are most popular for economical and effective microsampling.