Hello,
One of my single hung sliding window channel balancers broke at the spring holding pin and nylon chord. The window weighs 24 lb and the balancer is approximately 28" long. The broken balancer is stamped with "28D". I assume your model
S770-28 would do the trick, but the ends on my balancer look a little different than what is pictured on your website. I would like to verify it is the correct balancer prior to ordering four balancers.
Thanks,
Pedro