Cap Insert, for Diffusion caps, for 4 mL vials, 12/pk: 470151-286 – Vial, Flint Glass w/Screw Cap, 7 mL, 17 mm x 60 mm – Glass Vials with Screw Caps – Pack of 12 $13.31 Juvale Plastic Vial 100 Pack – Plastic Tube with Blue Screw caps – 5 ml Vials, Caps