Glass Threaded Vials found in: Vial Sample S / T w / PTFE Cap 16ml Cs144, Screw Thread Glass Vials, 9mm Clear Glass Screw Thread Vials, EPA Water Analysis,.. 8-425 thread design Original, narrow neck size Uniformly flat bottoms ensure compatibility with inserts Vials are available with black caps and a variety of septa to meet your application needs.