I need some help.
Hello there. This is a coil balance system, which regulates the window's movement. Specifically this is a 15-177 Pivot Shoe, which uses Series 152 Coil Balances (all these components are sold separately, so you only have to replace what is broken). If you need any new coils, you have to choose specific spring weights for each replacement. These spring weights denote the weight each individual coil can support. Look for stamps somewhere on the coils that should indicate this. If there is none or you're unsure, give me the exact weight of the window sash that these coil balances support, and I can work it out for you.
If you need new coil covers, see our newer style 15-143, 15-144 and 15-145. These parts 'sandwich' around each individual coil spring.
If your old springs are marked with a 7, then they should be the 7 pound option. With two on each side that means you're looking at a 28 pound sash. I'd suggest checking that to verify; as long as your sash is 28 pounds then using the 7 pound option for each spring should be fine.