- Headspace Screw vial, 20ml Amber, Vial, screw top, headspace, amber, round bottom, 20 mL, 23 x 75 mm, 100/pk. Vial size: 22.75 x 75 mm (18 mm cap) Aijiren headspace vials are constructed from type 33 and type 51 COE borosilicate glass, with low metal content, to protect your sample from destablizing or leaching.