These wetsuit boots and made out of 3mm neoprene which is a stretchy material,perfect for making them a great comfy fit and keeps you warm. They have a nice strong zip on the side which makes them easier to put on and off. Also they have a very strong grip on the sole of the boots to prevent from slipping and tripping and they cover the ankle. Ideal for general surface water sports use. 3mm neoprene Strong zip on the side Very strong grip on the sole Ideal for general surface water sports use.