IST 3mm 12mm Thick Felt Sole combines the utility of a sturdy felt sole with the comfort and flexibility of a 3mm neoprene upper. Hard, thick felt soles provide traction on jagged, slippery coastal reefs and ensure a good grip for clambering up slick boat ladders. Boots with 12mm(0.4&&';;&&';;) thick felt sole. 3mm neoprene with ROTEX upper Great for walking on slippery coastal reefs Glued and blind stitched seam to minimize water flow.