Mix and match different sizes; units stack and connect together to form a custom modular system. Transparent bins tilt out and stay open while in use. Can be wall mounted or used on countertop. Identification labels (except One-Bin) and mounting hardware included. Bins can be easily removed from locking mechanism for cleaning and refilling. Plastic. Overall 23-5/8w x 5-1/4d x 6-1/2h.