Review on Organize Your Closet with GRANNY SAYS 2-Pack Large Clothing Bins - Blue Storage Bins for Laundry Room and Living Room by Chris Burks

They are very heavy duty, with synthetic materials for the outer skin (nylon I think) and metal braces around the top and along each side corner. The handles are strong too. There is an MDF (eg pressed cardboard) insert on the underside, which provides a solid base, while the inside is lined with a smoother material (the outside is a bit rough). We've used Kirkland K-Cup boxes (they're about the same size) to store things like K-Cups, and these baskets offer the best access. Overall we are very satisfied with this product. P-)