This pack of 6 Tracer Replacement Pencil Leads (4x 2B and 2x Yellow) are designed for use with the Tracer Deep Hole Construction Pencil. These 120mm replacement leads are highly durable and snap-resistant, and effectively mark wood, plastics, ceramic and metal. The 4x 2B graphic leads are ideal for marking dark lines on lighter surfaces, and the 2x yellow wax leads mark clearly on darker surfaces.