READY FOR ANY MISSION, ANY ENVIRONMENT, ANY TIME. Developed side by side with the United States Marine Corps, the RAT (Rugged All Terrain) earned its name among elite warfighters as being the only proven USMC rugged all-terrain boot available. Precisely crafted with highly durable nubuck leather, a tear-resistant 1000 Denier nylon, an abrasion-resistant polyurethane reinforced heel and toe cap, and an advanced Vibram 360 Dri Ice outsole, the RAT embodies Danner's commitment to crafting higher standards. We recommend women select 1.5 to 2 full sizes down for correct fit. Please be aware that these boots tend to run narrow. For this reason, we recommend sizing up by at least half a size or going with the next wider fit available, depending on your preference.