Constant / counter force spring

Thanks for posting. I believe you may have our 15-087 Coil Shoe, but you'll want to remove the shoe from the window and compare the dimensions, particularly the width and thickness, to what we illustrate below. Let me know if anything differs. If you do indeed have the 15-087, this shoe works with the 15-086 Housing and uses Series 180 Coil Balances. For the replacement coil springs, you need to select spring weights. These are determined by stamps on the coil springs themselves (not the stamps on the housing). If there are no stamps or you are uncertain, provide us the exact weight of the window sash that these balances support, and we can work out what you need. Let me know if you have further questions.

Detail of 15-087