27" which part number of yours do I need ? photo shows 26 3 bsi rp I also shot a picture of the lower part of the window .
Bob from SWISCO responded:
September 7, 2021
See our S380-27 or S385-27. The only difference between these two channel balances is the depth of the bottom nylon shoe, or 'heel-to-toe' measurement, so compare both with your old hardware to see what matches best. For a new stamp option choose 2630.