Nalgene™ color coders are made from polystyrene and fit only in Nalgene™ cryogenic vial closures. Available in 5 colors
Nunc™ color coders are made from polycarbonate and fit only in Nunc™ cryogenic tube closures and Cryobank 2ml and 5mL tube caps. Available in 10 colors or as an assortment.