These mailers are a bit on the thin side. It wouldn't take much for a cd jewel case to rip through the bubble wrap and outside paper. You'll still need to add cardboard on each side the jewel case or risk a cracked jewel case in transit.
Just the right size to pack a couple or even 3 jewel-boxed CDs. Some bubble-pack sizes are a pain to pack where you have to stuff them and it takes longer than it's worth. These are easy to use for mailing CDs and or DVDs.