Black Knight Ion Radium PSX Squash Racquets : The Black Knight Ion Radium PSX squash racquet offers solid performance and quick play. Youll experience enhanced power and a large sweet spot. Reinforcements at key points allow for fine-tuning of the weight and balance. Features reduced frame distortion and torque. Provides enhanced stiffness and vibration dampening qualities. Prestrung with Supernick XL.