Replacement coil

Hello, Chris! That's correct, that stamp tells me that your coil can hold 9 pounds by itself. These add up per spring, on both sides of the window, to give you the kind of tension you need to hold the sash up.

As for what the spring is, I can't say for sure. It resembles quite a few that we sell. I'd be happy to look into it for you but I'd need additional information. To start, I need you to measure the width of the band and tell me what you get. It should be either 3/8" or 1/2". I also need to see a clear photo of the pivot shoe.

Perfect, thank you! Seeing the design of your shoe, and knowing that the spring is 1/2", then I am very confident that our S160-9 coil spring is what you want. Each of these springs individually holds 9 pounds, as described above.