The 5.11 A/T 8” Side Zip is a performance boot built from the sole up to increase performance. The All Terrain Load Assistance System (A.T.L.A.S.) is a force multiplier for those who carry heavy weight on long shifts. The boots were developed to work with your "work weight". This boot is constructed of nylon with high abrasion air mesh, a water resistant leather upper, and because so many professional jobs demand it - a polishable toe.