ROLL N LOCK M Series Retractable Truck Bed Tonneau Cover Installation Guide Roll N Lock M Series Manual Retractable Tonneau Cover LG223M RealTruck Roll N Lock M Series Retractable Tonneau Cover 5' 6" Bed W Rambox ROLL N LOCK M Series Retractable Truck Bed Tonneau Cover Installation Guide. From its retractable function, which permits opening or closing in literally seconds, to its rigid, vinyl over aluminum laminated construction, this hybrid cover offers everything other covers do not for your 2019 Chevrolet Silverado 1500. 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 no worries about the security of cargo. The Roll N Lock retractable truck bed cover is by far the most intelligent and versatile tonneau cover that Roll N Lock makes. Features Industrial grade vinyl overlay over aluminum slat construction Compact, ultra low profile 7. 25 in. deep canister preserves valuable truck bed space Patented built in tailgate locking system Torsion spring drive makes opening the cover effortless Patented, ratchet style latching mechanism enables three latching positions Keyed, twist lock latch with unique key slot coverprevents snow and rain from entering or freezing the lock Integrated pull strap for easy closing from outside of the bed Patented contoured hinge provides maximum security Simple clamp on installation 3 year limited warranty