Hi What do i need?

Hello, thank you for posting,

Your windows use an older rod balance that is no longer made. We recommend converting to the Series 775 channel balance. You will need to measure the length of the rod and width of the bottom shoe attachment. You will also need to obtain the weight of the window sash. Once the length is determined review the product page to choose the correct stamp option from the strength chart. 

Please review and let me know if you have any additional questions!