The two-bar, M1000 Series roof racks are designed to mount to any fiberglass pickup truck topper cap. The included poly foam gaskets are placed in between the mounting bases and truck cap to prevent water from leaking into the truck bed. Interior metal plates are used to secure the roof racks the the truck cap. These truck racks come in durable steel and are available in lengths of 60", 72", and 88" cross bars. A black or white powder coating is added to extend the life of the cross bars and protect against harsh weather.