Coil springs broke on both sides of window

Thanks for writing in. I agree the 15-192 is the correct pivot shoe. This is compatible with our Series 170 Coil Springs. Based on your spring's stamp number you might need our S170-405, which supports 5 lbs of weight individually; but if you're uncertain this is correct, weigh your window sash. Give us that exact weight, and we'll work out precisely what you need. Many thanks.