Thanks for getting back to us. I went into our warehouse and there will be no lead time for the 25 4 balances you show in your photos. In will send you a separate email with a link to order two of these balances. As for the other window with the missing balances, we'll need to do some more investigating to figure out what you need and if we have them in stock.
First, please confirm that these are identical windows made by the same manufacturer other than the size.
Next, go to the window with the balances we've identified from your pictures and measure the height of the visible glass in the sash.
Then, do the same thing for the window that is missing its balances. If we can make a connection between the size of your window with balances and the length of the balance that's currently installed, we should be able to make infer the size of the balance needed for your smaller window.
We'll also need the weight of the sash for your smaller window to determine the strength that the spring needs to keep the sash raised.
With this information, we should be able to infer the size that you need and if there will be a lead time associated with those balances. Keep in mind that since the balances are missing, there is a margin for error and we can't guarantee that you won't run into unforeseen problems when installing new balances. If you'd like, I can send you a custom order link today for the balances we've identified, or e can wait to figure out your second balances and I can send over links for all of the balances you need. Please let me know how you'd like to proceed.