These are 3 mil thick thermal laminating pouches for use with thermal laminators. It is a letter size pouch in a 20 pack for retail accounts.Scotch Thermal Laminating Pouches protect documents that you use frequently. Protects and adds professionalism to business documents. Great for signs, flyers, schedules, certificates, to-do lists, and other frequently used documents. Ultra clear to let important information show through. Ideal for marker-proof, tear-proof and spill-proof paper items that you want to last in the home, office or classroom. Recommended to use with Scotch Thermal Laminators.