Koh-I-Noor Gioconda Artists' Drawing Chalks Leads / Sticks are is mainly intended for use with mechanical pencils. These leads blend easily and are extremely easy to use. They allow you to produce a smooth, beautiful texture. Each lead has a round profile of 5.6 mm diameter and measures 75 mm in length. Box of 6 - Includes - 8673 - Soft / Medium Charcoal, 4865 - 2B / 4B / 6B Graphite Lead, 4345 - Medium Black Drawing Lead