The picture says it all. These are the older and thicker CD jewel cases - you can even remove the plastic insert that holds the CD in place. The latest very thin jewel cases will not work except for the thinnest of flies. Easy to stow, see flies at a glance and ideal for small flies or flies without barbell or hourglass type eyes. The cost of these jewel cases certainly beats those expensive Fly Boxes (although nicer) in the shops.