DURABLE ALUMINUM: 'Speed Bumps Ahead' signs are made of 63 mil thick heavy-duty rustproof reflective aluminum that easily lasts 10 years outside and meets DOT road and traffic requirements. EASY INSTALLATION: All signs come with rounded, burr-free corners and 3/8 inch punched and pre-cleared holes. Signs mount to U-channel posts, square or round galvanized posts, wooden posts, and chain-link fences. LAMINATED PROTECTION: With lamination, graphics are protected from weather and abuse to preserve a fresh look. Graffiti can be cleaned off too. Clear UV laminate resists chemicals, UV rays, water, and abrasion. 3M AUTHORIZED: Signs use official 3M Reflective Engineer Grade film and are printed with 3M screen printing or 3M outdoor digital inks designed specifically for outdoor traffic and property signs - providing ultimate quality and assurance. PACK CONTENTS: One 18 x 12 inch black and yellow aluminum sign.