3M AUTHORIZED. Official 3M reflective films and inks on durable, rustproof aluminum ensure that our signs meet all DOT requirements for outdoor parking and traffic signs. DURABLE ALUMINUM. Heavy-duty rustproof aluminum has a 10-year outdoor durability rating backed by a 3M warranty. LAMINATED. Graphics are protected from weather and abuse. Graffiti can be cleaned off. Laminated signs outlast competitive unlaminated or overcoated signs. INSTALLATION. All signs come with rounded, burr-free corners and pre-punched/pre-cleared holes. Signs mount to U-channel posts, square or round galvanized posts, wooden posts and chain link fences. GIVE A HEADS UP. This Children At Play sign reminds drivers to be cautious and alert while driving through areas where children often play, such as schools or playgrounds.