Easy operation, tail header rail and bows roll up with tarp and secure in place at cab rail. Security Strap holds tonneau tightly at the cab rail when open. Velcro Fastening System holds the tarp securly to the frame. The Tail Header (shown just ready to rotate down into place) tightens the tarp and locks onto the latch. Pulling the latch-strap releases the header and allows the tonneau cover to be rolled up. With a locking tailgate and the latch-strp tucked into the tailgate, the system cannot be rolled up without a key. This added level of security will prevent access to the truck bed except by vandalizing the tonneau system. The Tension Control allows adjustment of the tension of the tonneau cover with the changing of the seasons. The inside mounting of the tonneau rails provides complete access to the top of the truck's bed rails. This allows full use of accessories such as side rails or pocket-mounted cargo tie-downs.