Three octavo vols. Each is an uncorrected proof copy issued by Bloomsbury as early forays into the marketplace. In this regard, certainly the response to Harry Potter and the Philosopher's Stone was far different from that experienced by the sequels. The publisher's expectations are reflected in the proof designs. For the first book, the format is very much of stock quality, but the later editions pay homage to the series: Harry Potter and the Chamber of Secrets has a wand at its upper cover, and Harry Potter and the Prisoner of Azkaban has a half-title and title-page with the Hogwarts crest. Together the trio admits a view into the early years of the series' production and its rapid rise to prominence.
Philosopher's Stone in white wrappers with yellow band and text in black; creases at either side of spine, minimal, if any, soiling, else fine. According to Errington (AA1[a]), the print run for this proof is estimated at 200 copies. Chamber of Secrets in deep blue wrappers with white band and illustration and titling in black; some rubbing along edges, faint crease to lower right corner of upper cover, else fine. The print run for the second book is also unconfirmed, but "between 200 and 300 copies" is "suggested" by Bloomsbury (Errington AA2[a]).  Prisoner of Azkaban in the second binding of green wrappers with white band and black titling, with text corrected from the first appearance in purple wrappers; minimal soiling to both wrappers and edges of text block, creasing along sides of spine and lower corner of rear wrapper, else near fine. Errington posits between 150 and 250 copies printed (AA4[b]. All are clean internally. Housed together in custom morocco clamshell box.