Replacement window balance

Thanks for posting. This is most likely either an S380-14 or S385-14. The difference between these two channel balances is the depth of the bottom nylon shoe, or the 'heel-to-toe' measurement. See the illustration below for reference. Compare both with your old balance to see what matches best. In either case, for a new stamp option go with 1350.

Comparison of the S380 and S385 balance shoes.