A New York Yankees cap worn by Babe Ruth around 1932 could realise more than $300,000 at Goldin Auctions.
The sale closes on August 8.
It was given by former Yankees manager Joe McCarthy to a young newspaper delivery boy named Robert O'Brien.
The auction house explains: "The cap presents as one of the finest Ruth hats on market with extremely superlative provenance."
Ruth is baseball's most iconic figure and the value of his memorabilia is increasing year on year.
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