Astrox 22 RXEnsures a stronger more flexible frame, while increased shaft flex creates maximum power. Pre Strung AERO+BOX Frame combines a solid hitting feel and quick swing ISOMETRIC racquet generates a larger sweet spot by optimizing the intersection of the main and cross strings. ISOMETRIC delivers greater control without sacrificing power. the counterbalance theory, weight is distributed throughout the grip end, frame top and the joint for maximum control.