Cartridge arrangement comprising an adapter

The cartridge arrangement of the present invention enables recording and/or playback apparatus to be used with cartridges of various sizes, the cartridges being provided with releasable locking means and, after the release of such means, being able to be opened to permit the tape roll(s) to be rotated on the recording and/or playback apparatus. The cartridge arrangement is applicable to every type of recording medium in tape or strip form in systems employing cartridges in which there is a need for using cartridges of various sizes, especially in the case of the recording and playback of magnetic signals.