2 mL Screw Vial & Cap Kits: SureSTART Certified EPA Screw Vial & Cap Kits: SureSTART Certified Scintillation Screw Vial & Cap Kits: Standard 2 mL screw top vial-cap kits; including SureStop vials with AVCS caps: 4, 8, 12, 16, 20, or 40 mL vial-cap kits: 20 mL screw top vials with 24 mm caps : Innovative technology ensures proper vial-cap seal every time