Correct Cover for 2026 Keystone Cougar 360MBI

Updated 04/03/2026 | Published 03/30/2026

Question:

trying to find the correct cover for a 2026 Keystone Cougar 360MBI - 393 L x 134 H at nose

asked by: Robert C

Expert Reply:

Robert, you’re asking the right question because getting the fit right is what keeps a cover from flapping, rubbing through corners, or trapping moisture.

I did look up your trailer on RVUSA, and your 2026 Keystone Cougar 360MBI is 39 feet 3 inches long, so we want to go off that measurement rather than the 393 inches. That puts you right in the ideal range for a cover that fits 37 to 40 feet. I recommend the Adco SFS AquaShed 5th wheel cover part # 290-52257. This size will give you a snug fit without being stretched tight, and it’s designed with straps and cinch points to pull everything in so it stays secure in the wind. The material is breathable, which helps prevent moisture from getting trapped underneath, and it has reinforced areas around the front cap, ladder, and other high-wear spots so you’re not dealing with premature wear. It also has zippered panels on the passenger side so you can still access cargo compartments or get inside for winterizing without removing the whole cover, and you can unzip the rear panel as well to load and unload gear.

I would not go up to a larger size, since extra material is what usually causes flapping and chafing. This one will give you full coverage and still tighten down properly so you can trust it to protect your trailer.

Where will you be parking it most of the time, out in the open, a windy area, or under a carport?

expert reply by: Heather A