Identify property, communicate safety and warning messages, and display bar codes with these durable ID labels. TrueBlock Technology completely covers everything underneath so you can relabel items. Extra-aggressive adhesive stays permanently attached so they are ideal for extreme temperatures and high-traffic areas. Labels are made of polyester that is moisture-resistant, scuff-resistant, tear-resistant and smudge-resistant. Easily customize labels with free online templates and designs using Avery Design and Print. Letter-size sheets are compatible with laser printers. Each sheet includes four labels (5" x 3-1/2").