Coextruded or COEX tubes are similar to monolayer plastic tubes except there are multiple layers of extruded plastic with a barrier layer on inside the tube.

Tubes are also meant to protect the product from the environment. COEX tubes are advanced plastic tubes specifically made for products that are more finicky and need extra protection. The barrier layer inside protects even the most susceptible products from UV rays and other environmental pollutants. They offer better protection from the environment with the same positive properties of regular plastic tubes.