Emily from SWISCO responded:
June 15, 2021
Hi, Marissa. That stamp is quite weird. A stamp that begins with a '28' usually indicates a balance that is 29" long, not 30". Can you double-check that length? You can always weigh your sash to determine the appropriate spring strength option. There's a chart on the Series 751's product page that shows you which option you'll need based on the weight of your sash. If your sash weight differs from our given weight options on the chart, we can look into a custom option. |
Paul from SWISCO responded:
June 18, 2021
Thank you so much for your patience while we looked into this. I just have a few questions before I recommend moving up to the S751-30. The balance you received, does the balance channel overall size match besides the length? Does the balance knife shoe also match? If so, then go up to our S751-30 with a 29HD spring weight. The spring sash weight will hold between 22-28 lbs. |