What are Truck Tool Boxes? When you're on the road, your truck will become your second home. You have tools, securement supplies, and other belongings you carry with you that you need to store safely - however, you must be careful that these supplies and their storage don’t take up too much space when kept in the cab of your truck. You can’t be comfortable in a cluttered cab! When you attach a trailer storage box under your flatbed, on the tongue of your trailer, or mounted elsewhere on your truck, you’re creating more space while keeping the supplies you need secure. A lot of truckers often opt for the topside tool boxes or the side mount tool box; .