BP 1/2" plugs are for use in plugging holes 1/2" diameter in sheet metal. These plugs are mainly used in P.D.R. or Paintless Dent Removal or Repair. These are a very nice high-quality plug and give a hole a nice clean finished look and they also add a finishing touch. These plugs are very high quality and do not have flashing or rough areas on them. Manufactured and packaged in the United States. DIAGRAM MEASUREMENTS A .29" B.85" C .55" these plugs are made of plastic.