M&G has many different aluminum flow through vents varying in length and depth. These vents are great for allowing air movement through the trailer to allow constant fresh air. These vents vary in dimensions and are $49.99.
Replacement Vent Cover
Replacement roof vent cover, 14"x14" fits several different manufactures of roof vents. These covers are $19.99.
Maxx Air Vent
Maxx Air Vent , 14"x14" let's fresh air in anytime...rain or shine! The Maxx Air Vent allows the roof vent to be open without being ripped off during harsh weather, prevents heat buildup, proven super-tough one piece design. $49.99