Desiccants and anti-corrosion bags are a must for humid climates and damp storage conditions inside cases. The watertight seal can actually work to keep moisture inside a Pelican™ case, especially if parts are being put away wet. That is why desiccants and vapor capsules, when left inside your Pelican™ case with your gear, can dramatically prevent rust and degradation of material stored inside Pelican™ cases. Peli Desiccant Silica Gel "drinks" dampness, prevents condensation from trapped air when cases are opened in damp, high humidity climates. Fits all cases.