Excellent performance - Aluminum pans provide even heat distribution as well as quick heating and cooling. Convenient - Great for cooking large amounts of food. Lightweight - Easy to move around. Galvanized wire edge - 1.0 mm thick rim that prevents warping and keeps the pan flat. Sturdy - Each tray is 18 gauge commercial grade aluminum (beware of thinner models). Baker's racks - Fits all standard restaurant rack tray slides. Not intended for standard home ovens due to size. Includes: 12 - half sheet baking pans - 13" x 18"