3mm neoprene upper and 5mm neoprene insole Maximum warmth and comfort, whole sizes only Durable, high-traction rubber sole for support and traction Gusset-backed YKK zipper for easy on and off Back neoprene panel color-coded by size The NRS Comm-3 Wetshoe - The NRS Comm-3 Wetshoe is a simple neoprene booty offering support, protection, and insulation from the put-in to the take-out. A 3mm neoprene upper combines with a 5mm neoprene insole to provide maximum warmth and comfort while the rubber sole offers support and traction on wet rocks and gravel.