Steel cylinders are the ultimate. Steel's superior strength allows significantly thinner wall thickness than aluminium tanks meaning a smaller and lighter overall package for the same internal volume. Faber Cylinders are manufactured from steel plate to ensure lighter cylinders with the right buoyancy. No other steel manufacturer in the world can match Faber's capabilities and range. You can significantly reduce the lead you need to wear due to the extra negative buoyancy of steel cylinders making for a more comfortable dive. Yellow is the only colour option Nitrox use: The 3L, 5L, 10L, 12L, 12.5L and 15L cylinders are approved for filling with Nitrox to a maximum of 40% oxygen at 15 degree Celsius. Under no circumstances are these cylinders to be filled with a greater oxygen content. Please note that the 3L and 5L cylinders do not come with a tank boot. The photo is an indication only and is not to scale.