Use these solid, dense plastic hole plugs to fill the unused binding screw holes left after mounting new ski bindings with a different mount pattern.  Plugging the unused screw holes is critical to keep snow and water out of your ski's core material which can freeze, expand and cause major damage.  Drop a dab of waterproof (PVA) glue into the unused binding screw holes then firmly tap in a hole plug with a rubber mallet. Trim the remaining plug material off flush to the ski's top sheet with a sharp wood chisel, razor blade, or utility knife blade.