Gunnison DryboxThe Down River Equipment Gunnison Dry Boxes are built with 0. 080" thick aircraft grade aluminum, resulting in the strongest, most durable box for its weight. No hangers are required as each box has built in tabs that rest on the frame rails. Shoe box style lid with rubber gasket ensures the box will stay tight and as dry as possible. Length: Measure narrowest point of boat width at apex of your tubes for max width. We recommend going 1 2" narrower