Vials: 20ml, Headspace Amber Screw Top, 100/PK Vials are manufactured from Type I borosilicate glass and accept 18mm precision thread screw caps. These 20ml, 75.5 x 22.5mm, MicroSolv brand, amber headspace vials are CTC GC PAL, Aijiren, Gerstel, Shimadzu, Thermo, TriPlus & Perkin Elmer 20ml