The Universal Storage Cart is designed to store up to 40 (1″) rest mats, 20 (2″) rest mats, 1416 PlayPanels (any size), or a 12″ Module Blocks Set A or B. Built with a powder-coated, heavy-duty rust-resistant steel and wire frame, this cart is durable and dependable. It glides effortlessly on four 3 rubber casters, two of which lock for stability. Some assembly is required. NAP MAT STORAGE: The universal storage cart is ideal for storing toddler nap mats, and can hold 40 (1 inch thick) or 20 (2 inch thick) nap mats. (Sleeping mats sold separately.) QUICK & EASY TO MOVE: This rolling cart has four 3 rubber casters, 2 of which can lock, so you can roll with ease and make sure its secure in place DURABLE DESIGN: This cart organizer is constructed from a sturdy steel and wire frame, as well as a rust-resistant, blue powder coating to ensure this cart will endure many years of use VERSATILE DESIGN: This teaching rolling cart is also perfect for storing our 40 Take Away Seats or 12 Module Blocks Set A or 12 Module Blocks Set B (Sold Separately)