Searching for 2120 bsi l

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.

Thanks for getting the pictures over to us, Mike. It looks like you'll need our Series 385 balance. Measure the just the metal channel without the plastic attachments to determine what length you'll need. Hope this helps!