Dan Espen wrote in
:

I see Duraseal is also a window type.

I had a similar problem.
I went to the NAMI website, downloaded a PDF and found the
manufacturers name using the number in the PDF.

At first the manufacturer wouldn't help, they wanted the retail
outlet to act as a go between, but eventually they came through.

I cannot find a PDF on that site. The key numbers on the NAMI sticker
a

Code: KKI
Specs: NRFC
Series: 4600 Double Hung
MST: 3050