Derwent Onyx Pencils Derwent Onyx is made from smooth, dark graphite & delivers dense, rich, jet-black tones, darker than a Graphic 9B. Due to its non-crumbly texture, the 4mm wide core is capable of sharpening & holding a fine point. This makes it equally good for quick expressive sketches, as well as detailed technical & architectural drawings. Darker shades can be built up by applying increased pressure. - Round 8mm barrel - Wide 4mm graphite core What's in the box 2 Medium & 2 Dark Pencils, Sharpener & Eraser