Notice the difference in angle on the front face (bevel) or the bits. The upper bit is great for wood. It peels off wood like a knife blade, but it is too "grabby" for acrylic, and produces a pitted surface. The Lower bit is great for acrylic, you can peel endless ribbons off the hardest of the Trustones and M3 blanks, but this tip leaves a ragged, torn surface on wood blanks.