No scratches: The protective plate has a 12.5mm/0.49in high baffle to prevent hand scratches. Material: Aluminum alloy ruler is oxidized, durable, lightweight design, suitable for office and home use. Clear scale: The scale is laser-calibrated, not easy to fade, and is clear and easy to read. Anti-seepage design: It can avoid the structure marking when the ink penetrates due to the ink drag phenomenon..syi