flat bottom headspace gas chromatography and cap. Headspace Vials, Standard 22 x 38 Crimp Top - Thomas. 20mL Amber Flat Bottom Headspace Vial, 23x75mm, 18mm Thd list price/quantity total $453.31 / CS (1000 / CS) Perkin Elmer), Beveled Bottom, 20mm Beveled Crimp Top list price/quantity total $30.63 / PK (100 /.