These non-porous Ceylon graphite cores are dense and durable. The core is Carbo-Welded to withstand four times the normal point pressure. The specially treated cedar wood casings sharpen easily. Pencils are pre-sharpened. Kit includes three Kimberly graphite drawing pencils (2B, HB, 2H), one Layout ebony pencil, and one All Art Eraser. Conforms to ASTM D 4236. Made in USA.