We can definitely supply this balance, but it will have to be a custom order due to its configuration. Before we go any further, can you just tell me how many you needed? Can you also confirm that the length of the metal channel is 20-7/8" long?
I'm not certain that the S395-21 will work, unfortunately. I've had a lot of customers try out something like this and it rarely even installs properly; in those few instances where it does seem to operate okay, it usually breaks after a few months of use.
The major difference between your balance and something like the S395-21, aside from general design and size, is the length of the cord. Your original balance has a cord with an extended travel; the more standard travel of the balance you just purchased from us is probably going to be too short. In a best case scenario, your sash won't close. In a worst case scenario, the cord will pull out of the pulley and the balance will be irreparably damaged.
You may want to return that for a refund, but it's up to you. You can see our return policy here.
Thanks for the information. I will email you a purchase link and price quote now that you can use to add 2 of these to your cart. Let me know if you had any other questions and I would be happy to answer.