Window balancer

Hi my name is Jackson and I need to replace my window balancers. What is the difference between your 1504 and 1505 shoe attachments?
Also, my old ones measured 30" as per your instructions and are marked as follows: 29 3 BX CMC 11.

I think I need your series #385 please advise, thank you.

Yes I meant 15-004 and 15-005. The image with measurements I had not seen so this is the information I need. Thanks!