This triple-protected finish provides long-lasting durability. The process includes a zinc galvanizing spray, followed by an epoxy paint and then a top coat of polyurethane. The result is a beautiful cosmetic finish.Faber steel cylinders are cleaned at the factory for oxygen-enriched service up to 40% pre-blended Nitrox. If you intend to use this cylinder for oxygen-enriched service, it is the responsibility of the cylinder user to insure that the cylinder and all components are maintained in a proper state of oxygen cleanliness in strict accordance with regulatory requirements and industry standards.Features: 3442 psi (237 bar) working pressure Phosphatized-cleaned interior DOT Special Permit #13488 and Transport Canada #SU7694-237 approved Oxygen cleaned for use with up to 40% pre-blended Nitrox High quality, injection-molded custom tank boot with round rim