GSI 1/4" Window Kerf Bulb Weatherstrip Mount Slot Seal in 2 Colors and 6 Lengths (500, Black)

Perfect replacement for dried out South facing windows.

well i had some doors that were leaking a lot, and needed something. I did not want to spend $350 for the installation router tool. So i experimented with an oscillating multitool, and it worked great. I fits insterted a 1 inch wide blade into the multitool, positioned it into the door jamb and held it at a 45 degree angle so it would go into the jamb, and not the stop. Then cut a groove all around the door jamb. Then i inserted a "grout remover" blade into the multitool, and recut the groove to be just a little wider. That turned out to be the exact size the kerf needed to insert easily (with a screen roller tool i found at the hardware store), but would not pull out easily.

A LOT cheaper than what the manufacturer "Marvin" wanted for the same thing. Plus, they wanted to come and install it for hundreds of dollars. No way, this was a piece of cake, no need to pay hundreds for a dumb installer to come do it, it's so easy.

I did a lot of research to find this weatherstrip to replace the old stuff in my windows. This one is not super easy to install, which is good. It fits into the channel snugly. The old weatherstrip had shrunk and stiffened and was coming out. The new stuff gives a fresh bounce to my windows as I close them. I have to push down a little extra to get the locks closed, and that’s just how it should be.

Used this weatherstrip to replace disintegrated seals around our 30 year old crank-out Kolbe & Kolbe casement windows. Not exact but seemed to fit the application.

Fast delivery just did not fit where I Wanted to use

A couple of my window double-sash wooden window frames had rotten out so I was making new ones for them. I wanted to make sure they were more weathertight than the old ones. Routing a 1/8" dado was all I needed to do to get these to fit. No more drafts!These are great if you have the ability to route a 1/8" dado -- either by using your tablesaw or if you have a router. If you don't, then you should just use adhesive weatherstripping.

My windows are 18 years old and the kerf is falling apart. I got 100 feet and changed every window. No more air leak nor ladybugs.