Bob from SWISCO responded:
September 17, 2020
This appears to be either an S380-35 or S385-35. The only difference between these two balances is the depth of the bottom nylon shoe, so compare both with your old hardware to see what matches best. For a window sash that weighs 35.4 lbs, I advise you choose a stamp option of 2965, which supports a window sash in the weight range of 35 through 39 lbs. |