tilt window balance
A quick learner from New Brunswick Canada says:
June 21, 2016
Stamped with 02/10 Unique 20-C-30 and is 21" in length
Paul from SWISCO responded:
June 23, 2016
Thanks for posting. I'm having trouble making out exactly what kind of balance you have. Can you confirm what kind of channel it has, either ribbed or plain? If you aren't sure what I mean, please show us a closer picture of it from an end-facing angle. That will allow me to confirm. I would also like you to tell me its width and thickness. Finally, there should be a shoe that it attaches to, perhaps still in the track. Could you show me a picture of yours?