We use The Mechanics Pullman. Basically it consists of a bottom unit which measures approx. 20"high x 24"wide x 8"deep. The bottom unit is for bulky items and has 2 wheels. The top unit measures approx. 16"high x 24"wide x 8"deep. It has two lift out trays. A clear hinged top with many compartments and a hidden swivel out drawer which also has many compartments.<br><br>The top attaches to the bottom unit using clips on each side. The unit also has a folding handle that allows the unit to be used like those pullman suitcases that are dominating our airports.<br><br>I have modified ours slightly to enable them to be attached to the Canadian and A.L.I.C.E. pack frames with the shelf attachment.<br><br>We keep 4 of those units in our house. They fit perfectly in the corner of our closets. You know, that forgotten corner where all the old clothes go.<br><br>Three of our units are special purpose but one is multi purpose and to give you an idea of storage capacity we keep 1 single burner propane stove, one single mantle propane lantern, two small, camping propane cylinders, 24 inch prybar, folding saw, 5&10 inch visegrips, 4 knives and 4 multi tools, candles, lighters, matches, asst. flashlights, heavy duty med kit, sewing and fishing kits, AR-7 and some, other asst. hardware in one unit. <br><br>The beauty of the unit is that it can be rolled along even ground by a fairly small child. It can be carried attached to the packs by in shape adults. And if you are in a real hurry you can lighten the load by using only the top or the bottom of the unit. They are not weather proof but their design means that they can be covered by a large garbage bag or weatherproof cover.<br><br>Available from Walmart in black. Available from Canadian Tire in yellow or red. Cost between 30 and 60 dollars.