Window balance

Thanks for posting. Looks like you might have either an S351-33 or S390-33. The only difference between these two channel balances is the 'depth' of the bottom nylon shoe, or the 'heel-to-toe' measurement. See the diagram below for reference. Measure your old balance's shoe depth to see what matches best. For a stamp option, choose 3240.

Comparison of the S351 and S390 balance shoes.