Green and White Mailbox Sign 911 Reflective House Number sign. Prismatic 3M/Engineer grade material. Made in USA Double sided to be seen from both sides of sign. .040 gage aluminium. Material live 7 yrs and beyond. We welcome customization request. Engineer Grade Prismatic reflective sheeting Non-metalized, microprismatic lens, reflective vinyl covering Better daytime and nighttime brightness than beaded engineer grade sheeting Solventless manufacturing process, significantly reducing VOC emissions and energy use Designed for commercial and non-critical traffic control signs and work zone devices Meets and exceeds ASTM D4956 Type I specification