Spiral Balance inquiry

Hello, thank you for posting,

It appears that your window uses tilt spiral balances. I cannot confirm the diameter from the picture, but you could have either the 5/8" diameter Series 600 or the 3/8" diameter Series 900 spiral balance. 

You will need to confirm the diameter and the length of the metal tube to determine the right fit. Also review the bottom of the tube for a colored tip that indicates the strength of the spring needed. If there is no colored tip, you will need to obtain the weight of the sash and compare to the strength chart on the product page to choose the correct option.

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