Finally the racquet used by the queen of tennis herself is available for all to useThe all new Wilson Blade 104 Countervail Serena Williams Autograph provides the perfect mix of power and control for the modern game What is Countervail Technology and what does it do you might ask Countervail is an allnew material technology used by NASA for space travel integrated into the racquet to maximize a players energy reduces muscle fatigue and shortening recovery time It does this by transferring less of the balls energy into the players body which decreases the amount of energy you need to expend on each swing With Parallel Drilling technology this racquet provides improved feel minus harsh vibrations the Blade 104 guarantees both comfort and performance This racquet measures in at a lengthy 28 inches plus the 104 square inch head size will give a bit more margin for error without sacrificing precision and placement The 18x19 string pattern provides a blend of spin and precision thanks to the larger head With a slightly head light balance this racquet is maneuverable but stable great for a baseliners just like Serena Williams