Flexible stacking system allows you to build as many trays as you need. The trays can be stacked using risers, self-stacked straight or staggered, as well as stacking in reverse or at 90º. The angled base ensures paper stays securely in place and aids easy retrieval of papers. The Avery Desk Tidy can be fitted onto the top tray to provide extra off-desk storage. Avery Black Desktop products are environmentally friendly - Manufactured from 100% post-consumer recycled polystyrene, they are also 100% recyclable.