These are Simonton Windows installed in 2001. Th spring on the right side of the window broke. I sent them a message and they sent me the following reply:
Thank you for contacting us. I looked up your order number and the balances you would need are size 25B 25B.
Can you help me with a replacement part. I'm fairly handy but if you think this is a difficult fix please let me know.
Thanks, Dick