Ours is an Adco. They seem to be the big manufacturer of covers. Shop around online when you decide. We ended up ordering ours from Camping World and getting their Presidents club card to get a discount. Shipping can be expensive. We went with the "Designer" cover that is tan with a graphic on the side apposed to gray for only a few dollars more. There are differences in material that depend on what climate you live in. Ours is Tyvec but we (for now) have it parked most of the winter in a nasty climate.
Take a close look at anything that sticks up and might poke a hole through. The little arms on one slide topper put a couple in our brand new cover. Two tennis balls with a knife slit fit over them and would have saved us patching it.
Mark & Nancy
2004 Winnebago Vectra 40KD
Shep dog, R.I.P. Kenzie dog Toad 2015 Jeep Wrangler Willys Wheeler