Milgard Casement window exterior bubble seal

Handy Person from Kauai

Jul 7, 2023 1:25 pm

They're series 5520 C-C20/C-C40?

I've attached photos of the channel the seal slides into and measurements of the seal.

5 user uploaded images

10 Replies

Quick Learner from Kauai

Jul 7, 2023 1:56 pm

I've attached photos of the location of the seal and dimensions/profile.

5 user uploaded images

Emily from SWISCO

Jul 10, 2023 9:28 am

Thanks for reaching out to us. We've come across this seal before but I'm afraid we were never able to track down a good match. The options I've related on this page appear to be our best options but they are still very different so we're not optimistic they would work. I am very sorry for the inconvenience.

Emily from SWISCO

Mar 31, 2026 2:36 pm

I'm afraid we've never received confirmation as to whether the related seals worked or not. If you decide to give them a try, our return policy can be found here, just in case.

Quick Learner from Raymond WA

Apr 1, 2026 3:09 pm

I believe the 58-200 will work. I just ordered a section of that and will let you know if it works because I will be buying lots more if it does. Thanks for your time and help in this metter. Jim.

Emily from SWISCO

Apr 1, 2026 3:20 pm

Thank you for your order! It means a lot to us. We look forward to hearing your feedback!

Quick Learner from Raymond WA

Apr 15, 2026 12:48 pm

Unfortunately the 58-200 did not work. The kerf is slightly too small for a good tight fit and the flap is not quite wide enough and doesnt fill the gap properly no matter which direction I install it. I think a 1/2 inch bulb or foam filled may work if it had a larger kerf. The kerf on the existing meausures 1/4 inch across but the slot it fits into on the window is 1/8 inch for a tight fit. do you have anything like that? I cant send the order back because I cut off about three inches to test the fit. Thanks, Jim.

Emily from SWISCO

Apr 16, 2026 9:01 am

Unfortunately, we don't sell a seal that meets the specifications that you need. Contacting Milgard directly may be worth a shot, though we can't make any guarantees. I am very sorry that we can't supply a suitable option.

Quick Learner from Raymond WA

Apr 20, 2026 1:02 pm

I'll retract the post that stated the 58-200 will not work. After further testing I placed it on with the flap towards to outside of the window and it's seems to be exactly the right fit for the 3 inch section I tested. I will test one whole side next. But I believe this will actually work for a direct replacement for the old style. Jim

Emily from SWISCO

Apr 20, 2026 2:28 pm

That's awesome to hear, Jim! We appreciate your feedback, and I'm sure others with the same seal will find this very helpful.