We can go by the internal spiral in this case. If the total length of the internal spiral is 26" - then go with our S600-25
In your image the internal spiral looks to be 26" (but make sure that the internal spiral was not pulled out of the tube a little bit, which would make it appear longer in your image.
Let me know if my explanation is clear.
Thanks Paul.....Everything is clear, I will order the S600-25.
Thanks again for the help.
Rich M.
Paul, Thank you for your help with your recommendation on my spring balances. It was right on and your service is great. I ordered them (S-600-25)on 8-25-11 and got them on 8-31-11, installed them in two windows in about 10 minutes each and no more holding up windows with sticks. Great company and I'll recommend to all my friends. Again, thanks for all your help. Rich
Thanks for following up with us.
I'm glad to hear the balances worked out for you.