I use the Crafter's Companion EZMagnetic 2-N-1 Set (Full Size) It is a plastic binder that holds the 2 N 1 magnetic panels that you can put your dies on. For added versatility, 2-N-1 panels hold clear and cling rubber stamps on the reverse side. So you could use the binder for either dies or stamps. It snaps shut and holds a ton of dies. I love it!
EZMagnetic 2-N-1 Starter Set (Full Size) - Includes 1 EZBinder & 2 Storage Panels