A BRIEF HISTORY FROM WIKIPEDIA:
The original CD single (sometimes mini CD single or 3-inch CD or CD3 in the US) is a music single released on a mini Compact Disc that measures 8 cm (3.1 in) in diameter, rather than the standard 12 cm (4.7 in). They are manufactured using the same methods as standard full-size CDs, and can be played in most standard audio CD players and CD-ROM disc drives.
[...] Capable of holding up to 20 minutes of music, most mini CD singles contain at least two tracks, often consisting of a single edit and an instrumental version in the same way as 7-inch vinyl singles.
KING OF POP:
Here they are the only 3inch cd singles released for the Dangerous album. "Black or white" is the most common (although still considered a rare press), while "Remember the time" and "In the closet" (especially the latter, complete with the french tour sticker as you can see it in the pictures) are the rarest. The Showroom is proud to own these 3inch still in their original EPIC blister, with 2 red stripes on both sides of the blister.