The product in question is....
Cakewalk Sound Center: Jupiter 8 by DSF (Digital Sound Factory).
this product is old and it's for Music Creator. it will work with Sonar and almost all versions of Cakewalk Sonar.
here is the link on the digital Sound Factory website which has a demo song to listen to.
http://www.digitalsoundfactory.com/jupiter-8-0 cheaper on Cakewalk at $14.95 on sale right now.
it's just okay. it's NOT a Jupiter 8 but it's some sampled sounds from the Jupiter 8.
Like most Digital Sound Factory products they are okay and dated now. they used to be top of the game and very diverse product line - now I don't even install anything I had purchased of theirs or that I have from Cakewalk. There are better libraries out there and much better sounds.
The Mellotron product is here and pretty much same review above:
http://www.digitalsoundfactory.com/mellotron-0