Which part to order

Thanks for posting. The stamp you give us only tells us the strength of the springs. Which is to say, how much weight they can support. I'm not sure what Series you need though. This is determined by the nylon ends on each end of the balance. Could you show me a clear picture of each of yours?

Can you also confirm the weight of your sash? I suspect it's 36 pounds but I want to be 100% sure.