Identify a part

Hello, thank you for posting,

For the coil balance, please review the style and dimensions of the 15-251 inverted support along with the Series 160 coil spring. 

The length overall height differs, but it should still work for your window as long as the width and thickness of the support matches up. Based on the stamp, see the S160-07 coil spring that can support 7.5 pounds of weight. 

I do not recognize the other part shown. Do you have a picture installed or can provide more detail of where it installs/function on the window? Thank you! 

Measurements of 15-251

I'm afraid the 15-251 would be the best we can offer. I am very sorry for the inconvenience.