Until now, estimates of their age have varied widely. According to the British Museum, the plates could be anywhere between 300 to 2000 years old. In any event, taken together the series of 66 stone plates contain the entire Book of Ezekiel, with only a few notable variances in wording compared to today’s accepted Hebrew text. These do not change the message of the prophet to any extent, but they may provide hidden clues to Jewish scholars on certain mysteries surrounding the prophet.
Editorial note: This mentions the Dead Sea Scrolls as the oldest known Hebrew text. There is actually one much older: The Silver Scrolls discovered by ABR staff member Gordon Franz at Ketef Hinnom.