Alpine Window balance replace

I'm not able to make a recommendation based on the glass size alone. Alpine has used our Series 385 in the past, but there's no guarantee that this is what you have. If it is, I would recommend our S385-13 with a 1220 option. I would prefer to see a picture of your existing balances removed from the window, if you can. Are both balances missing or just one?

If both balances are missing then all we can do is make an educated guess. Like I said, the S385-13 is a possibility, but I cannot guarantee that it will work.