A system includes a carrier system adapted to be worn by a user and to support at least one of a plurality of differently sized tanks of breathing gas, a bracket connector attached to the carrier system, and a plurality of brackets. The carrier system may, for example, be part of a breathing apparatus such as a self-contained breathing apparatus. Each of the plurality of brackets has a different configuration. Each of the plurality of brackets is attachable to an associated one of the plurality of differently sized tanks and to the bracket connector. For each one of the plurality of brackets, an assembly that includes the one of the plurality of brackets and the associated one of the plurality of differently sized tanks, when attached to the bracket connector, positions the associated one of the plurality of differently sized tanks in a predetermined manner relative to the carrier system.