Flipside Plastic Welded Letter Trays - Plastic Welded Letter Trays handle supplies and materials, paper storage and organization. For added strength and rigidity, trays are sonically welded at key stress points. Compact, nestable design allows you to stack multiple trays to minimize used storage space. Place letter-size paper, documents and other essentials in the tray to easily access items. Effortlessly carry and transport trays using handles.