We are attempting to replace the balances of 2 windows. They are marked C 28 BSI. We also need to replace the top sash guides, but cannot identify it. We believe the channel balance is a 2830. Here are pics of the balance and the sash guide that we are attempting to replace. Please let me know what other info helps. Thank you.
Paul from SWISCO responded:
March 22, 2012
Thanks for posting! For your top sash guide, please take a look at our 18-156 Gapco top sash guide. Make sure to compare its dimensions to your own hardware.
As for the channel balance, please look at our S351-29 with the 2830 stamp option.