Bathroom double hung

Thanks for writing in. This looks like the 15-180 Pivot Shoe, which uses Series 190 Coil Balances. You'll need to choose a spring weight for each coil spring you're replacing. A stamp on the spring should indicate the spring weights you need. If there is no stamp or you're uncertain, give me the exact weight of the window sash and I'd be happy to work this out for you. With this coil system you only need to replace what's broken; but if you need a new housing assembly for the coil springs, see the 15-181 and 15-182.