"Caution - Use At Your Own Risk" Sign By SmartSign | 12" x 18" Aluminum DURABLE ALUMINUM. Signs are made using 63 mil thick aluminum and do not bend easily. They have been proven to outlast the toughest of storms. Signs last 10 years outside. ROUNDED CORNERS. Signs have rounded corners and burr-free corners for safe handling, longer life and a professional appearance. PROMOTE SAFETY.Signs speak volumes about your commitment to everybodys well-being by promoting safety. 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 and pre-cleared mounting holes for easy installation. Signs mount to U-channel posts, square or round galvanized posts, wooden posts and chain link fences.