THE DUKE'S SAW SALVAGE MOLYBDENUM DISULFIDE COATED PISTON.  LESS OVERALL FRICTION AND CYLINDER WALL WEAR.  MOLYBDENUM DISULFIDE IS COMMONLY KNOWN AS "MOLY" OR "MOS2."

AWESOME QUALITY PISTON WITH THE STIFFER CAST IRON RINGS AND BEST QUALITY PIN CLIPS. 

The moly coating is seen as a sacrificial lubricant and creates a surface that is slicker than the traditional bare aluminum. What this creates is a lower friction surface overall and as long as the coating remains on the piston it is quite clear there is no skirt wear.

Long term you'll see less overall skirt wear, less heat and friction and less overall plating wear. The moly coating is industry standard in performance ATVs, Dirtbikes, outboards, etc.