Magnetic tape cassette having a protective plug to avoid erroneous

Abstract

A magnetic tape cassette includes a sliding member, a stopper for preventing the sliding member from being disengaged and a positioning click stopper for engaging the sliding member at a switching position at which an erase possible condition and an erasure preventing condition are chosen, the prevention stopper and the click stopper being independently provided between the sliding member inserted into an aperture in the thickness direction of the cassette casing and the insertion aperture bored through the cassette casing. The click stopper is formed of a stop portion and a guide portion continuous to the stop portion so that the switching operation of the sliding member can be performed smoothly. Thus, the magnetic tape cassette can be placed in the erase possible condition and the erasure preventing condition easily and positively. Further, when the sliding member is pushed too strongly in the switching operation or when the sliding member is worn, this sliding member can be prevented from being disengaged and the erasure can be positively avoided.