Neoprene Providing warmth and durability, NRS 3mm Outfitter Bill wetsuits go beyond the professional standard. Insulated with 3 mm neoprene and color-coded for quick and easy size selection. Constructed of 3 mm nylon-coated neoprene for warmth and comfort. The front-entry zipper for quick on and off doubles as a relief zipper. We've added rugged ToughTex material to the seat for extended durability. Featuring knee pads for additional abrasion resistance. Color-coded chest for easy size identification.