Milgard Window Balance

Thanks for contacting us. Can you confirm the exact weight of the sash this balance supports? Can you also confirm that the metal channel is exactly 33" long? If it's something like 32-5/8", you may need something else.

If it is 33", then the S385-33 should be fine. Based on the stamp you have, the sash weight may be 42 pound, but I would still like you to weigh the sash just in case. There are two possible options that can work for a 42 pound sash: our 3270 and 3275, I'm just not sure which would be better in your case. Knowing the exact weight would confirm.