High quality 12" x 18" sign made of strong rust free .040 aluminum,Excellent waterproof and dust-proof ability, Very durable and lifespan will be more than 7 years. | This "Slow Down Speed Limit 15 MPH" sign, Clearly and visible black with Yellow design, helps remind drivers see it from a safe distance away and slow down immediately and reduce danger. | This sign have 2 pre-drilled holes, It is very easy to mount in wall or fence or gates. | Professional and beautiful sign with reflective coating , in the night light will shine.