Presco 6 inch Marking Whiskers are an alternative marking choice for survey and construction sites, underground utility locating and many other uses. Virtually indestructible, these APWA color-coded Marking Whiskers spring back up when run over by lawn mowers, graders and heavy equipment. They are easily and conveniently attached to wood stakes or to 60-penny nails (not included). Use them alone or in conjunction with other marking products. Insert a 60-penny nail through the circular opening of the metal clip, then hammer the nail into the ground or Hammer a wood stake into the ground. Hold the Marking Whisker at the end opposite the metal clip and hammer the metal clip into the top of the wood stake.