2 diff sizes
A quick learner from Ocala FL says:
August 15, 2016
The first window measures 26 inches from end-to-end not including the plastic... That's to say the metal part only. Markins show 25 DS 37. The shorter one 24 inches and 1010 metal only not including plastic. The markings show 23 90 26. Thank you in advance for your help
Tom from SWISCO responded:
August 17, 2016
Thanks for posting. This looks like our Series 395 channel balance. Check it out and see what you think. I'm not sure about the discrepancies in the sizes. I recommend carefully double checking your measurements, as well as weighing your sashes on a scale to determine the proper spring strength option.