PVC outer, laminated to a woven nylon inner lining, making the material super-strong & rip-proof, whilst remaining light weight. Unique new seam welding technology - seams are fused together with an integral tape, using a new Sonic Welding process. Finished seams are immensely strong, but also almost completely flush, to avoid any seam-chafe. Heavy-duty, PVC boots with a deep tread, cleated sole for a sure grip in most conditions.