Features the plastic and spongematerial, which has high durability, not easy to deform. -Material: Plastic, Sponge. 3 Pcs Artist Blending Sponge Pen Rubbing Sponge Brush Sketching Sponge Brushes. 4pcs Blending Sponge Pen Washable Double Headed Sponge Brush Sketch Wipes.