§  25.18  Trail  grooming  equipment; requirements. Any combination of
  equipment used to maintain the snow surface of snowmobile  trails  shall
  be equipped with:
    1.  a  head  light  and  tail light as required of snowmobiles in this
  article, as well as a  revolving,  rotating,  flashing,  oscillating  or
  constantly  moving  amber  lamp with a minimum candlepower of sufficient
  intensity to be plainly visible from a distance  of  five  hundred  feet
  from   the  front  and  rear  during  hours  of  darkness  under  normal
  atmospheric conditions; and
    2. reflector material as required for snowmobiles.