4. These are the multiple heavy-duty hook and loop fasteners. Trust us, you only want to attach the rug to these fasteners once. If, for some reason, the hooks attach themselves to the Bedrug, they are very difficult to pull loose. However, the plus side to that equation is that even if the Bedrug goes into a truck bed without a tonneau cover, and these are specifically designed for exterior use without a tonneau cover, the Bedrug is assured of not flying out while driving down the freeway.