This plate fits many of the four, five, six, seven and eight pin raw sockets we sell without collars. There is no obvious way to fasten the plate to the raw phenolic sockets. Maybe a spring steel 'wavy washer' or epoxy? Plate measures 1mm thick, screw mounting centers 38mm. Inside hole diameter 29.3mm. Rounded portion on the outside of the plate measures 36mm. Widest end measurement 48mm.