need replacement channel spring assembly

Thanks for posting. We can help replace these channel balances, but they'll have to be custom made because none of our stock non-tilt window channel balances support a sash weight of 50 pounds. I'd like to just confirm a few details before we proceed. Are you confident the fittings on your old balance match the 19-005 Top and 15-004 bottom, the fittings used on the Series 385? If in doubt, send pictures. Also, is there a stamp code anywhere on the metal channel? If so, can you show us? From there I will get a quote prepared for you.