Thanks for posting! The part installed in the window is referred to as a locking terminal. This is installed to the bottom of the balance channel and is used to support the sash weight. If you are looking to replace this, the entire balance will need to be replaced. That said, I'll need to see this removed from the window to provide you with the correct recommendation for your balances.
This video tutorial can be used as a reference for how to remove and install these balances. Once you have them removed, I'll need to see the attachments from the top and bottom of the balance and the stamp from the metal channel.
Hi,
As mentioned above, to be able to provide you with the replacements you need, I will need to see your channel balance removed from the window. I cannot identify the replacement you need using the photos above. Please take a look at the video provided for instructions on how to remove the balance.
The shoe you have will need to be attached to the balance as a custom assembly. These balances are non-refundable and cannot be returned if they are incorrect. That said, it is important for me to see the whole assembly.
Please let me know if you have any questions.