Mountain High 1365l (CFFC-048) Carbon Fiber Filament Composite Cylinder
The Mountain High carbon-fiber filament composite (CFFC) cylinder has an aluminum core with a carbon fiber wrap and are DOT-E 11194-2216 rated.
Carbon fiber cylinders are lighter than aluminum and a little more expensive. In Europe, the CFF-480 can be compressed up all the way up to 3000 psi, meaning more significantly more available oxygen. Carbon fiber cylinders have a service life of 15 years (if they pass hydro testing every 5 years), after which they should be retired. One exception: the CFF-480 requires testing every three years.