The Yomega Brain is simply the best yo-yo ever made. It features a centrifugal clutch mechanism that causes this yo-yo to snap back to your hand automatically, enabling you to effortlessly master auto return throws. You'll also get prolonged spin time with the most advanced auto-return technology ever created. The Brain comes with extra replacement string and measures 6cm in diameter. Includes a detailed trick handbook with illustrations to get you spinning like a pro.