A box of six, Two Star table tennis balls manufactured by Halex, a division of the British Xylonite Company, circa 1950s. Vacuum formed in two halves from cellulose nitrate. The illustrated box has an endorsement for the product from Johnny Leach, world singles champion 1948-49 and 1950-51. A statement on the box reads 'Two Star. Manufactured under strict control and tested at every stage by Halex (a division of the British Xylonite Co. Ltd.) London, England, makers of Table Tennis Balls for over 50 years. Approved by the English Table Tennis Association, and used by leading players throughout the world. Johnny Leach always chooses a Halex Ball'. Each ball is also endorsed on each half.