Bob from SWISCO responded:
July 14, 2020
This looks like an S351-22 or S390-22. The only difference between these two balances is the nylon shoe depth, so compare both with your old hardware to see what matches best. You'll have to choose a stamp option. That stamp code looks possibly like 2130 to me, which would support a window sash in the weight range of 12 through 15 lbs. Let me know if that is right or if you have any other questions. |