Most of these chimney top covers are made of aluminum or vinyl blades or both are touching together so they can be rolled up. Always reminds me of a roll top table. Most retractable tonne covers stop almost where you want them to, rather than having to open or close them all the way. Water flows from the cover and onto the side of the rail, which acts like a gutter and pipes water toward the back and away. There is usually a drain hose attached to the tube and down through the plug hole in your truck box. This will remove water entering the tube.
Chimney top covers have a similar appearance to the way they were built. They have two rails mounted on the side of the truck covered by the lid. There was a tube stretching over the truck bed just behind the cabin. It is located so it is quite flat with a cover for a nice sleek look. Roll cover within the tube to open and exit the tube cover.
There are a range of chimney top covers that may be pulled on the market. Many pickup truck owners like this type of cover because it suits their daily demands. The overall design of the tonneau cover that can be pulled is quite unique so you might agree if you see it.