Very robust design for professionals with a thick wooden casing and a wide graphite lead. Lead hardness 10 H (= extremely hard) for less abrasion on rough surfaces. For marking hard surfaces such as stone, brick, and concrete. Made from high-quality limewood. This soft hardwood is very well suited to sharpening, and offers an optimal combination of stability and flexibility. Field of Application: Construction, installation Design: Oval Content remark: 12 pieces