27-D-40 Balance Rod

Thanks for reaching out to us. If your old balance is 28" long, then you want a 28" balance. 27" would be too short. The 28D stamp option may be what you want but you should weigh your sash on a scale to confirm. We have a chart on the S770-28 store page that tells you exactly how much weight each option supports.

I'm not sure about the shoe, but the S770-28 is commonly used with the 15-129. Carefully compare our dimensions to yours to confirm that it matches.