Abstract: A deactivating device for magnetic markers in an electronic article surveillance (EAS) system includes a housing adapted to constrain typical audio and video cassettes in preferable orientations with respect to first and second deactivating surfaces. The first deactivating surface includes a first magnetic insert, which includes a first magnet designed to produce a deactivating magnetic field which deactivates markers affixed to audio and/or video cassettes without causing audible signal degradation of the prerecorded magnetic media within the audio or video cassette. The second deactivating surface includes a second magnetic insert and second magnet designed to produce a deactivating magnetic field which deactivates markers placed in the recessed edge of video cassette without causing audible signal degradation of the prerecorded magnetic media contained in the video cassette. An alternate magnetic insert which can be substituted for the first and second magnetic inserts is also described.