External Thread Cryogenic Vials These Corning® vials are manufactured from polypropylene to withstand temperatures to -196°C. Vials have a silicone washer for a secure seal. Vials can be colour-coded with inserts (see Cat. No. 430499). All self-standing vials have a special base design allowing them to be locked into the cryogenic rack and tray (Cat. No. 430525) for single-handed manipulation. Sterile, certified non-pyrogenic. Packaging: 50/pk 500/cs