Aijiren provides Screw Thread Headspace Vial always be applied to Aijiren, Shimadzu, Tekmar, CTC PAL, Varian, Gerstel, Atas, Thermo Scientific autosamplers. Aijiren’s Screw Thread Headspace Vial are all round bottom, this is because A rounded bottom is more sturdy and thus more resistant to the high pressure within the vial during the heating process.