2. Adding the end of S after the product name indicates that the SET technology patented by Wilson is used, that is, the spin effect technology. By changing the thread bed, the horizontal line is smaller than the vertical line, which makes the thread bed more open and increases the rebound speed of the ball line, so that players can get more topspin balls without changing their swing. Wilson's racquet has two kinds of wire beds, 16* 15 and 18* 16, and the Blade98S is 18* 16. Except for the different thread beds, the others are exactly the same as Blade98, but the hitting effect is completely different.