Each sleeve holds a Digipak with a spine of approximately 8mm.
*Digipak not included*
The clear plastic sleeves are similar to the ones you get in Japanese paper sleeve packages. They're great for using if you lose your sleeves from any of those, or if you've bought LP-styled CD packages from other outlets and want something to protect the CD inside. Antistatic, and very well constructed.
Naturally using CD 6mm jewel cases, the packaging bulk will be reduced and makes shipping and storage much easier.