National Scientific 4 mL Screw-Thread Vials National Scientific Preassembled Vial Kits. Combining top-notch and uncompromising quality with an affordable price the Thermo Scientific 4 mL Screw-Thread Vials Thermo Scientific Preassembled Vial Kits C4015-21/ 66033-022 can fulfill your laboratory needs while still offering a great value for the money. Vials are designed to fit Waters 48-position Shimadzu and other autosamplers that accomodate the 15x45mm vial format. Closures are available in polypropylene or phenolic resin. Convenience kits include vials and caps with pre-inserted septa. Preassembled kits have vials with preattached caps and septa packed in a reusable support tray. Certified vial kits are tested and certified to meet or exceed up to 17 critical performance parameters; certificate enclosed with kit. National Scientific 4 mL Screw-Thread Vials National Scientific C4015-21 Preassembled Vial Kits