An extremely rare $1,000 bill described as the “Holy Grail of paper money” has been sold at auction for just over $2 million, Fox News reported.

Auction house Stack’s Bowers Galleries sold the unusual bill for $2.04 million on Thursday evening at the 2018 Winter Whitman Expo in Baltimore.

The 1890 Treasury Note is dubbed the “Grand Watermelon” on account of the large green zeros on the back of the bill. Major General George Meade, the commander of Union forces at the Battle of Gettysburg, is shown on the bill’s face.

Only seven “Grand Watermelon” notes are known to exist. “The Grand Watermelon note is one of the rarest and most sought-after pieces of American paper currency,” said Stack’s Bowers President Brian Kendrella, in a statement. “This is one of only three known to exist in private collections and the finest example of its kind.”