These easy-to-read 1-1/2" Locker Tags are .020" thick and come with our super strong 3M adhesive on the back for a hold that just won't quit! Aluma-Tough (MetalPhoto) anodized metal tags stand up to the harshest outdoor elements and last 20+ years! Aluma-Tough (Metalphoto) aluminum tags have a glass-clear, sapphire-hard, anodic layer that seals the high-resolution image creating identification plates that resist abrasion, solvents, temperature, UV light, sea salt, and chemicals.