2021 - 08 - 19. The 8mm Screw Neck Vials with Magnetic Screw Seals for CTC is novelties in the crimp neck dominated Headspace market. However, especially for the hard to crimp magnetic caps, screw closures are a convenient alternative. The vials are preferentially used on instruments : CTC PAL , Varian, Gerstel, Atas, Shimadzu, Aijiren.