Window Balance Replacement Part
Hard to read but marking appears to be BSIN
28C
Thanks for reaching out to us! The window balances you have here appear to be an older style Series 795 Channel Balance. You can most likely use the S795-28 Channel Balance with a 28C stamp, but I'll need to see how it attaches at the top of the window channel to determine if it might need to be a custom assembly.
These balances are sold with the 15-195 1-1/4" closed cam shoe, but there is a possibility you may need either the 15-194 1" T-Lock Shoe or the 15-195B which is a 1-1/4" shoe with an open cam.
You'll need to remove the existing shoe to examine it and confirm the correct replacement between the three above. Their diagrams can be viewed on the website.
Please let me know if you have any questions!