Skulls cover these tuning pegs cast in solid white bronze.  Just unscrew your stock pegs, slide these over the tuning shaft, and reinstall the screw.  Fits Grover and Ping style tuning machines and others with the same shaft diameter.  Comes in a set of 6 tuning heads.  Please note, these are only the heads, not the tuning mechanisms.  Simply unscrew your existing tuning head, remove it from the shaft, and replace with skulls!