This 4 burnishing wheel is standard sized wheel (they fit standard burnisher). If you do not have a burnisher, no worry, since the conversion adapter can make your 5/8"-11 thread spindle grinder or polisher become a burnisher.    Please 100% make sure your grinder's or polisher's spindle is 5/8"-11 Thread. Please kindly refer to the  6 photo attached.  Please 100% make sure your grinder's or polisher's head collar diameter is between 41 and 48 mm. if less than 41 MM or more than 48 MM, the burnisher wheel protection cover does not fit.  This package carries (a)-(c): (a) 1 Piece of Burnishing wheel protection cover, (b) 4 Pieces of Burnishing Wheel: 1 X Grit 60 120 180 400.   Mainly used for the surface treatment of stainless steel, aluminum, copper and other metal products (c) Description:  This adapter attachment allows you to easily turn the angle grinder or wet polishing tool that you already own into a burnisher.  Simply attach the spindle onto your grinder, slide on the burnishing wheel and locking pins, and affix the locking nut.  Now your burnisher is ready to use!