5232208 window spring

Your pivot shoe looks like our 15-199, which itself is compatible with either the 1/2" thick Series 160 or 3/8" thick Series 165. Measure your old spring to determine the better match.

If you go with the Series 160, you also want the 15-150D cover. Conversely, if you have the Series 165, you want the 15-204 cover instead.

I'm not familiar with what your stamp represents. That's a weird one. I recommend weighing your sash on a scale and telling me what you get. Please be as precise as possible. With that, I can do a little math to figure out the proper spring calibration.