The Salvo 6-inch Waterproof Boot from Caterpillar runs one size smaller than most boots. Please select one size larger when selecting your size. The Salvo is built with genuine Goodyear welt construction on a slip-resistant T742 rubber outsole providing time-proven strength and ruggedness. Their oiled split suede uppers are lined with breathable nylon mesh for optimum performance. Poliyou liner provides the perfect blend of cushioning and breathability while wicking away moisture absorbing odor and inhibiting the growth of fungus and bacteria.