I have purchased several of these Itoya Profolio storage portfolios in several sizes, and I have always been happy with them. They come in many sizes and with varying numbers of pages, but the most common items have 24 two-sided pages that hold 48 items. The pages are polypropylene and the inserts are black acid-free soft heavy paper, so that these display units are ideal for archival storage. The covers have a large sleeve around the spine so that each "volume" can easily be labeled and given other identifying information. All-in-all, this is an excellent product that fills a specialized need.