DURABLE ALUMINUM. Signs are made from heavy-duty, 40 mil thick aluminum. Unlike steel signs, our aluminum signs do not rust. Signs last up to 7 years outside. ROUNDED CORNERS. Signs have rounded corners and burr-free corners for safe handling, longer life and a professional appearance. LAMINATED. Graphics are protected from weather and abuse. Graffiti can be cleaned off. Laminated signs outlast competitive unlaminated or overcoated signs. EASY TO INSTALL. Signs have pre-punched/pre-cleared holes for installation. Mount with screws, nails, tie-wraps or wires. Sign attachment accessories are not included. MADE IN USA. We have been making signs for over 100 years in the US. We know which signs work and which signs are durable outside. PROMOTE SAFETY. Use this Authorized Personnel Only sign to restrict entry to a confined space.