Window sash balance placement

I'm afraid I cannot identify what you have based on this information alone. The stamp only indicates the spring strength calibration and is not otherwise used to identify your balance. I recommend that you look at our Channel Balance Home Page and follow the steps in order to find the Series that best matches what you have. If you can't find a match here, please show us a picture of the top nylon attachment and a picture of the bottom nylon attachment and we will do our best to find a replacement. Thank you.