Paul from SWISCO responded:
June 10, 2021
Hello! Being in California, you most likely have a S385-16 channel balance with a bottom nylon shoe depth of 1-3/32". Please compare and see what you think. Now for the spring weight, your channel is marked "15 2" which carries a sash weighing between 6-10 pounds, but you said your sash weighs 20-30 pounds. We recommend that you weigh your sash with a bathroom scale to be sure. There's a chart on the S385's product page that shows you which option you'll need based on the weight of your sash. |