This is an original cast iron piston and rod for a John Lauson Frost King Jr or Alpha DeLaval Jr hit and miss gas engine.  The rod is part number JR 1 1/2HP.  The assembly is in excellent condition with no cracks, breaks, or repairs of any kind.  The wrist pin seems to have very little wear.  The original step cut rings seem to be in great shape and probably reusable.  The connecting rod bearing looks to be in excellent condition.  The piston is 3 1/2 inches in diameter.  Please measure your engine to be sure it works for your application.   These original Lauson parts are exceedingly tough to find in the wild or even at swap meets!  If you've been looking for one to complete a restoration or to replace your broken or repaired one here's your chance.  The pictures tell the story.  I can be reached at 262 573 193 1 if you'd like to talk about it.   Good Luck.