spring sash balance

Thanks for posting. This looks like a 15-111 Pivot Shoe, which uses either our 1/2" thick Series 160 Coil Balances, or the 3/8" thick Series 165 springs. Measure the thickness of your old coil tape to determine which coil springs you need. To know what spring weights to pick for each coil spring you purchase, look for stamps on the old springs. If there are none, or you're unsure how to proceed, please give me the exact weight of the window sash that these coil springs support, and we can work out what you need.