Karakal MX-125 Squash Racquet [Sports] by Karakal. Save 33 Off!. $113.95. Features the successful 'B' series inner 'Muscle System' which dramatically improves the control and power in the frame making even off centre hits feel like the middle of hte sweet spot. All frames have the 'Muscle Tec' string system. The MX-125 has an 'Internal Vibration Dampner' bonded into the frame to reduce vibration.