A deluxe 4cd set and a 2cd set. The annoying thing is that the 2cd set has a few songs that arent on the mega 4 disc version, so if you're a completist, you will need both and you end up with a lot of duplicate material. That is my only real problem with mofo, pretty much everything else about this box is fantastic. For me, the best part is the beautiul remaster of the original 1966 Stereo mix of "Freak Out!". The Freak Out cd that frank released in the 80's and is currently in print through rykodisc was a re-mix which sounds pretty good, but this original mix is much warmer and full of life. There is no contest as which mix I prefer, the original 1966 version is far superior in my opinion. The rest of the sets contains various alternate mixes, backing tracks, interviews, studio improvisations (all lead by Frank) and some early live recordings. There is one bonafide outtake "Groupie Bang Bang" which is as good as anything elese on the album. A great Bo Diddley type rhythm with hilarious lyrics (sung by Ray Collins) about, you guessed it, a groupie!