Series 800 stamp that reads "16BZ?"

A home owner from florida says:
I have a series s800 channel balance I ordered from you. It seems to work fine and looks identical to my old one. My only concern is that the old one is stamped 16BZ whereas the new one is stamped 16B. Is there any reason for concern?
Your company, website and customer care folks are just great, by the way!
Thanks, Trish
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Paul from SWISCO responded:
Thank you! Don't worry, you should be okay. The "Z" is the manufacturer's in-house code and doesn't affect the weight of the spring. I know that's a little confusing, so if you want to confirm you can always weigh your sash. Two S800-16 balances with a stamp of 16B can carry a window sash weight range of 7 through 12 pounds. As long as your sash weight falls within that range, you have nothing to fear.
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