OX Tools Tuff Carbon Marking Pencils are packed with features and are an excellent choice for any tradesman. The unique square design prevents the pencil from rolling off surfaces, unlike traditional round design. This pencil is designed to be able to write on almost any surface on a job site including metal, wood, plastic, brick, stone, block, concrete, glass, tile and much more. It features a belt clip and an integrated lead sharpener built into the cap. The pack comes with four leads, one standard graphite, one red, one yellow, and one white that can be used interchangeably.