Material:General sponge (polypropylene).seaweed/wood pulp/filtration sponge. Made of high quality and density foam. They are made of the acrylic fiber one side and another side is made of sponge. They will bring you double cleaning effect to help you make your bath comfortable. Acrylic fiber has property, which absorb oily. So they can easily get rid of foreign matters and oily things on skin. There are two characters. One is to be close to water. (Hydrophilic Property) The other is to be close to oil (Lipophilic Property) Lipophilic property part absorb to dirt and hydrophilic arranges to water. Soft and high absorbent texture increase lather with small amount body wash or soap.