The Mont Marte Hobby Knife Set contains three handles (heavy duty, medium and standard use) and includes 13 interchangeable blades. Mont Marte Hobby Knife Blades are constructed from SK5 steel to ensure excellent blade sharpness and extended durability. This set is perfect for cutting a wide variety of materials including paper, cardboard, fabric, leather and plastic. Great for sharpening sketching, charcoal and pastel pencils. Mont Marte Hobby Knives come in a plastic case with a magnetic strip to keep extra blades safely stored.