Holds Klein mid-size storage boxes. Boxes not included with rack- must be ordered separately. Welded- extra-rigid- all-steel construction. Metallic-gray- baked-enamel finish. Boxes ride in and out on heavy-duty channel tracks that permit covers to open all the way for full access. Heavy tabs prevent boxes from being accidentally pulled out- yet allow boxes to be easily removed when desired. Locking bars can be readily attached to prevent unauthorized access.