Window part

This appears to be either our S380-26 or S385-26. The only difference between these two balances is the depth of the bottom nylon shoe, or the 'heel-to-toe' measurement. Compare both with your old hardware to see what matches best. See the image below for reference. In either case, choose a stamp option of 2540.

Comparison of the S378, S380 and S385 balance shoes.