- Top Qualtiy Metal Pin Back Sets to create identification or recognition badges/ buttons. Each set includes metal shells, backs with pins and transparent plastic mylar covers. - 100 sets included in total. - Assembled button size is 2.25 inches or 57 milimeters. - Button Parts to be used only with Badge-a-minit, Hand Press Systems, Bench Press System, Badge-A-Matic, Badge-A-Matic II, and 3-in-1 Badge-A-Matic button machines