The MONO Natural Eraser is biomass-derived made from a minimum of 10% scallop shells! This new environmentally friendly eraser offers the same high-quality performance as the original MONO Eraser, cleanly removing unwanted lines and marks with little pressure and without damaging paper. The protective paper sleeve keeps eraser clean from graphite and other dust particles and is made with 70% wastepaper pulp. Great for art, school and office use. PVC and phthalate-free.