CTS has developed an innovative technology to produce a new kind of composite material cylinder “type 4”, made out of composite material, carbon fiber and resin, and underneath an ultralight liner made of PET (Polyethylene terephthalate). In this way the cost is diminished and the performances and reliability of the product are increased. CTS technology is the latest evolution in the development of the different productive methods, started with “type 1” cylinders (completely made out of steel or aluminium alloy), progressively evolved in “type 2” and “type 3” (structure with metallic liner) and lastly landed to the “type 4”. CTS has patented, internationally, a very reliable and economical competitive system to produce this new kind of cylinders with PET liner.