Hi I need help identifying and ordering this window Blanche

Hello! This pivot support appears to be a match for our 15-252. This part is designed to be compatible with our Series 160, so that would be my top recommendation.

Given the stamp of 20, it's reasonable to assume that you have two 10 lb. springs per side, suggesting a 40 lb. sash. However I would recommend that you weigh your sash on a scale before you buy anything just to be sure that's accurate. If it's not 40 lbs., let me know and we can figure out a better option for you. Better safe than sorry.