Bellows lock are fitted with furniture knobs with ABS system, to accompany the opening of modern interior doors. Thanks to this system, the latch does not get in the way and annoying efforts to open the door are avoided. How many times we find ourselves in situations in which lock and knob get stuck and we remain endless minutes trying to get out of the room. For this it is necessary to change the old door lock or directly the entire bellows door, in order to have modern interior doors.