From its retractable function, which permits opening or closing in literally seconds, to its rigid, vinyl-over-aluminum laminated construction, the Roll N Lock M-Series hybrid cover offers everything other covers do not. There are no snaps to manipulate, there is no roll or bundle to lash down or stow, no crossbars to negotiate, no fabric shrinkage to struggle with, no folding or solid hinged covers to combat, and, best of all, no worries about the security of cargo. The Roll N Lock truck covers – M-Series…by far the most intelligent and versatile tonneau cover made.