Diadem Sports Pro X ReelThis 200m reel is ideal for the player that frequently re strings their rackets and is looking to save money by buying in bulk. Strings 16. 5 18 rackets. Diadem Pro X is the most powerful and firm option for string in the Diadem line. Designed with the help of current pro tennis players, this poly string is designed to provide a stiffer option than the Flash string, with a hexagon cross section. The firmness results in an explosive response off the