Since 1988, MAXXAIR has produced high performance vent covers, ventilation fans and replacement shrouds for all types of RVs, from folding camping trailers, travel trailers, 5th Wheels and all types of motorhomes. MAXXAIR'S reputation is built on innovative, high performance and superior quality. The covers are constructed of high density polyethylene with maximum UV inhibitors for years of worry-free protection. Our vent covers are designed to fit over vents and allow you to travel with the vent open and keep the rain out and allow the fan to be used while traveling and in the rain.