need window balance replacement

Thanks for writing in. For your balance, see our S377-12. Make sure your nylon fittings match up with ours. Since your stamping does not correspond with any of ours, then you will need to weigh your sash on a scale and refer to the sash weight chart listed on the product page. Our 18-042 top sash guides can be used with this balance. Does your guide look like what we are recommending? Do your measurements match up with ours? Get back to us and let us know.