This wire squab diaphragm will fit all Minis built between 1960 and 1993 (before the twin post headrest seats were introduced). Originally the early Minis used a one piece moulded rubber diaphragm, however these are no longer available. The wire diaphragm superseded the rubber version item and can be used for a direct swap for all non reclining seats as it is supplied with the all necessary springs to hold it in place on the frame, however new holes will need to be drilled into the frame as per the diagram supplied.