This is the very rare first mono pressing of the UK issue of the Beatles "Revolver" album, featuring the rare alternate mix of "Tomorrow Never Knows." Evidently producer George Martin mistakenly mastered this album with the wrong version of John Lennon's psychedelic classic, and it was pressed for a day before Lennon caught the error and changed the version included. This rare first pressing is identified by the matrix number XEX-606-1 on Side Two of the disc. The disc is in Excellent condition, the cover is Near Mint