40mL 24-400 TOC Vial. 1. ND24 EPA Screw Neck Vials (Clear/Amber). 1.ND24 EPA Screw Neck Vials (Clear/Amber). 2.Available with black or white screw caps with 24mm thread. 3.Available as closed top screw seals or with centre hole. 1) Caps and vials are ideal for sampling and storage. 2) Caps are lined with PTFE/silicone for excellent sealability.