AAMA/NWWDA. Series: 510-550

We will do our best to help find a replacement balance, but we won't be able to identify it with the sticker on the window. If you have not done so already, you will need to remove the balance entirely out of the window. Once it is removed, come back and upload photos for us to see. Please make sure to include any stampings or markings that may appear on the part. Thank you. 

Thank you for your photos. However, they are too blurry for us to be able to make a positive recommendation. Is there any way we can see some clearer photos of the balance? We'd also like for you to provide the tube length and tube diameter of the part. Thank you.

Great and can we see some clearer photos of the balance? We need to see all the details of it, in order to be able to make a positive recommendation. Thank you.

Thank you for replying back with your photos. Based on your photos and information, it leads us to our S400-29 spiral balance. Have a look to confirm if this will work for you. In your photos, I don't see a color tip bearing to indicate which color option to choose. Therefore, you will need to weigh your sash on a scale and refer to the sash weight chart listed directly on the store page. 

According to the sash weight chart listed on the store page, it looks like you can go with the red tip.