I have to store everything I need for working in remote locations. I run light because there’s always a fully equipped crew onsite before I arrive. I wanted something cheap, easy to remove, durable. So I built my shelf from two adjustable shower curtain rods that fort into the rear pockets. Then built the shelf out of old decommissioned cellular antenna parts (aluminum back plates) that were dumpster bound. I’m very pleased with results, clothes, tools, climbing harness, helmets all fit in the back. Even had room left over for bicycle mount when not being used.