Searching for Alcon ballast

Hello, thank you for posting,

It appears that your window uses coil balances. Please start by reviewing the style and dimensions of the 15-111 pivot shoe that is compatible with either the 1/2" Series 160 coil springs or the 3/8" thick Series 165. Review the dimensions to confirm the best fit and let me know if you have any additional questions! 

Alternate image for 15-111