Double coil balancers

Thanks for writing in. This pivot shoe looks like our 15-180. This shoe is compatible with our Series 190 coil springs. Now unfortunately, I'm honestly not sure whether that's a 6 or a 9 stamped on the spring in your pictures! Do both springs have the stamp code? We don't carry a 9 lb spring weight for this series, but if it's 6 lbs, we have our S190-640. Ultimately, if you're uncertain the safest thing to do would be to weigh your window sash. Let us know that exact weight, and we can work out what you need.