The Faber 5L Steel Tank with Boot & DIN/K Valve is typically used with closed circuit rebreathers (CCR). It can, for example, be used with the Optima, Hollis Explorer, or Drager.
The small size of the cylinder comes in very handy, when doubling up. This size cylinder is also great for pool work or smaller kids (+10 y.o.), as well as a safety stage bottle to be deployed in various depths.
The leading European manufacturer of scuba diving tanks, Faber, makes these tanks from Chromium Molybdenum Alloy Steel adhering to high international standards.