The Castell® 9000 is the top-quality graphite pencil for writing, drawing and sketching. These pencils have superior leads made of finely ground graphite and clay. The break-resistant leads are smooth, never scratchy and the pencils are guaranteed to sharpen easily. The Design Assortment is ideally suited for drawing in the field of industrial design or fine detail drawings. The pencils are available in 16 degrees of lead hardness indiviualy or in assorted sets.