Hand-laid premium ZXT Rubber over a 5mm neoprene core for durable, flexible, waterproof comfort Zxt Rubber is ozone, abrasion and tear resistant with added tensile strength Active Fit with adjustable gusset for easy on/off and a secure, comfortable fit on foot Multilayer rubber on the toe, heel and vamp for added durability and support Non-metallic Safety Toe; metatarsal Guard and puncture-resistant midsole