Aijiren Tech™ Headspace Vials, 18mm, 12mL - Aijiren Tech Sci. Aijiren Tech™ Headspace Vials, 18mm, 12mL vial, glass. Available in 10mL and 20mL usable volumes this screw thread vial requires no tools for closure. Magnetic caps are ideal for magnetic pick up in autosamplers. Manufacturer: Aijiren Tech™ C4020180. Catalog No. 03-378-619.