This is an original cast iron piston and rod with cap for a small Nelson Brothers hit and miss gas engine. The rod is part number 3K6 and the cap is K16. The assembly is in excellent condition with no cracks, breaks, or repairs of any kind except half of the rod bearing has been replaced with brass that worked well as this was in a running engine. The wrist pin has some mild wear The rings need to be replaced as they are all mismatched. The piston is 3 1/2 inches in diameter and the 3/4″ diameter wrist pin is 2 1/8″ on center from the top of the piston. Please measure your engine to be sure it works for your application. These original 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.