A multi-chamber canister for a pressure swing absorption system within a general housing assembly. The chambers include a first molecular sieve chamber for receiving a first molecular sieve for separating air from the ambient environment into a concentrated gas and at least a second molecular sieve chamber disposed within the housing assembly for receiving a second molecular sieve for separating air from the ambient environment into a concentrated gas component. Furthermore, a supply chamber is disposed within the housing for receiving air from the ambient environment and for communicating air to either first or second molecular sieve chambers.