Bob from SWISCO responded:
June 23, 2021
Hello there. If you are certain the outer tube is 3/8" in diameter and 25-1/2" long, then I believe you need our S900-26; rounding up with spiral balances that end in X-1/2" increments works fine. For the Color Tip option, obtain the exact weight of the window sash. You can then match that exact weight with one of the weight ranges listed alongside each Color Tip option on the S900-26 shop page. |