Center Drain (CD) screw thread vials with hole caps and PTFE/silicone septa. Center Drain (CD) screw thread vials with hole caps and PTFE/silicone septa. Product Number. Product Description. SDS. 29327-U. volume 3.8 mL, clear glass vial, O.D. × H 14.75 mm × 45 mm, PTFE/silicone septa (bonded), pkg of 100 ea.