Series "513". Beautiful mainly pre 1940 collection, although some countries run up to the early 1960's. They are organized on quadrille pages with the scott catalog number written below each stamp. There is tremendous value in these country collections. Each quadrille page with stamps on both sides are mounted in a clear plastic sleeve to help protect the stamps. However, we did notice that some of the stamps are sticking to the page probably due to the way it was stored over the years. However, the stamps and the hinge can be easily loosened off the page. These are still wonderful collections, with lots of hard to find older stamps.