Need balance units for this window. it's a MW double hung window

I'm afraid I can't identify what you have based on this photo. This service needs a clear and unobstructed photo of the actual part you want to replace. In this case, you need to remove the balance from the window prior to taking your photos.

Once we see that, we can suggest a match from our inventory.

Please also note that balances can be complicated, so I might have more follow up questions for you. But first I need to know what to ask for.