I installed a Roll n Lock on my 1995 Dodge 4x4 diesel. Back then I think there was only 2 companies that made them, and Roll n Lock was the best at the time in my opinion. Over all it wasn't too bad, but the container eats up a lot of bed space. My bed was 8', so it was okay. Some of the "cons" were that it did freeze up in the winter. If it rained, then froze, or snow, the slats would freeze preventing it from opening. The lock would also freeze until i found a cover for the key entrance. Being black, and if the sun came out, it melted off pretty quick. But also being black, in the summer it got very hot and your fingers got quite warm when opening it. The other down side was, leaves and crud would work its way into the container and block the drain holes, so every so often I would have to take the cover off and clear the drains. Those are my observations from when I had mine. They made have made changes in them over the years, and several more companies are making them. It is a nice idea, and makes for pretty good security, but they are pricey.