I need a part number for these sash balances

Thanks for reaching out to us. When measuring your balances, you want to make certain that you are only measuring the metal portion excluding the nylon pieces at both ends. With that being said, your balance should only measure 25". I would reconfirm just to make sure. If that is correct, then I believe our S390-25 channel balance should make a good match for you. You would choose the 2420 option based on your stamping of "24 2". Make sure to get back to us and let us know how you made out.