2D Barcode Cryogenic Vials provided by STE-Mart are made from USP VI Polypropylene and feature HDPE caps. Each tube is permanently marked with a unique 2D barcode, ensuring the tubes can be easily and accurately identified when being moved, shipped or even accidentally dropped. Laser 2D barcode on the bottom of each tube allows scan and decode at once without removing from rack. Solid, one-piece construction ensures the barcode not fall off during the storage under low temperature. Every code is inspected to guarantee that is unique and readable.