Abstract: The present invention discloses an apparatus for adapting an electronic or electrical device enclosure for mounting on a DIN mounting rail having two opposed outwardly extending flanges. The apparatus comprises a DIN mounting rail bracket having provisions for attaching to the enclosure of the electrical or electronic device. The mounting rail bracket is provided with a hook for receiving a portion of one of the outwardly extending flanges of the DIN rail. The mounting rail bracket is also provided with a selectively operable locking and releasing mechanism opposite the hook for locking onto and releasing from a portion of the other outwardly extending flange of the DIN rail.