33I AI5 CMC 5 window balance

Thanks for your patience during this busy season. I believe our S770-33 channel balance and 15-129 shoe match up with your hardware. However, your stamp indicates a fairly heavy sash with a "33I" marking. Can you confirm for me the exact weight of your sash, down to the ounce? Can you also tell me how many you need? It may have to be specially made.

Well, we could specially make an S770-33 for you with a 33I option, but since custom balances can't be returned for a refund we usually like to confirm just in case. Since this balance broke only after a short time of operation, I think it may be a good idea to check just to be sure. Any common bathroom scale should do.

As for how many you need, the minimum quantity we can supply is 2. We usually recommend replacing both sides at the same time, anyway. You could always keep one aside as an emergency backup option. I still think there may be some problem with these balances, since they broke after only 6 months. This kind of hardware typically lasts a decade. If one side broke, the other side may not be far behind.

If you just want to go ahead with an order of two 33I balances, let me know.