I have Best Built windows (BBI-1); our house was built in 1998. The series:850;C-C40;MST: 3050.
The weather stripping that is currently in the windows is Q-LON. It has an I style channel insert that measures approx. .245" (wide) and the total width of the piece of weather stripping is approx. .570". It has a triangular foam body with the I channel at the bottom.
Window weather stripping

Home Owner from Fairbanks, Alaska
Jul 28, 2024 9:18 pm
4 user uploaded images
2 Replies

Jasmine from SWISCO
Jul 30, 2024 1:11 pm


Thanks for posting! Its a bit difficult to make out the exact shape of your seal from the photos and the drawing but I believe you may be able to use the 58-170B Foam Filled Weatherseal as a replacement. To determine if this will work for you, carefully look over the dimensions below and compare them.

Profile view and dimensions for 58-170B
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