These boxes are made of heavy duty one-piece industrial plastic that is rust, waterproof and corrosion-resistant; Reinforced side ribs add strength and prevent spread; Each storage box is easy to clean and can be used indoors or outdoorsStackable plastic bins maximize storage space, and extra-wide stacking shelves provide stability, save space, and prevent spills. Lidless open design allows you to easily see and access what's inside each compartment without taking them apart.Multi-purpose shelf boxes are great for classrooms, garage storage, food storage, craft storage, bathroom, kitchen cabinet organization, and closet storage; Suitable for storing cosmetics, office supplies, small toys, kitchen utensils or hardware.Usage: First, align the latches and slots of the two boxes and press down to assemble left and right. Next, insert the support frame into the support frame hole of the parts box. Finally, align the bottom hole of the parts box with the support frame and press down to assemble up and down.