Casey from SWISCO responded:
September 23, 2022
Hello, As long as the bottom fitting measures 1" deep, you would need the S380 channel balance. The 28" balances would need 2740 strength options. Your other two lengths have stamps from an old weight system that is no longer used, so you would need to weigh your sash to determine which option you'll need. There is a chart on the product page that explains how to choose your option based on the sash weight. Thanks for posting! |