Merrell Men's Chameleon 4 Mid Ventilator GORE-TEX Boot Nubuck Leather Upper treated with Aegis antimicrobial solution Gore-Tex Waterproof membrane provides impermeable but breathable barrier Moulded EVA - Merrell In-Board Compression Moulded EVA footframe provides supreme cushioning underfoot. Bellows Tongue - Keeps debris out. Insole - 2mm EVA insole for comfort and shock absorption. Stability Arm - External heel and instep stability arm.