Balances for Solaris double hung tilt-in window

After looking at your website, reading posts, and watching some of your videos, I am looking for help in ordering the correct replacement channel balances for my Solaris double hung tilt-in window.

Please see the attached photos of the top, bottom, and stamp on the unit.

The balance measures 26 inches from top to bottom and is 9/16 inch wide. Cam you please make a recommendation for the correct replacement part? Will your product code S770-26 with option 26D work for my window?

Thank you for sharing all of your helpful posts and videos!

Hello Casey,
I weighed my window sash, as you recommended.
It weighed 25 pounds, so I selected the 26D option.
I received the replacement balances and installed them yesterday.
My window now stays open, as it should.
Thank you for answering my questions and for advising me to weigh the sash.
I will recommend your company to anyone who wishes to make their own window repairs.
Keep up the good work!