A self-contained breathing apparatus includes at least one air tank having a regulator, and a back plate configured to removably receive the air tank. The back plate has a plate having a tank engagement surface for engaging at least a portion of an air tank, a receiving cradle on the plate configured to receive the regulator of an air tank, and a locking mechanism associated with the cradle and/or the plate for releasably locking the regulator and/or the cradle relative to the plate. The locking mechanism has at least one locking member configured to move between a first locked position, wherein the locking member engages the regulator and/or cradle to restrict removal of the regulator and/or the receiving cradle from the plate, and a second unlocked position, wherein the locking member disengages from the regulator and/or the cradle to permit removal of the regulator and/or the cradle from the plate.