This is an exceptionally hard to find original rocker arm or exhaust lever and pivot pin for a Fairbanks Morse Jack Jr or 1hp Type H hit and miss gas engine.  It is in excellent used condition with no cracks, breaks, or repairs of any kind.  It has some mild wear but should be ready to go to work for you.  It is part number 15ND2 and measures about 18 3/8" long overall.  If your rocker arm is broken, repaired, or missing here is a very nice replacement.  Jack Jr parts don't come along very often so don't miss your chance on it.  The pictures tell the story.  I can be reached at: 262 573 193 1 if you'd like to talk about it.  Good Luck.