Control the Roll with Thumb Chucks! Master your technique and learn tons of tricks. Thumb Chucks are composed of two high-bounce balls connected by a special belt. The chucks are interchangeable, allowing for unique customization, and each chuck contains a high-powered LED light that pulses with each impact, allowing you to play at anytime of day. Download the free app to view tutorials, watch Pros and film your own videos. Learn the first few tricks within minutes, but be careful, Thumb Chucks are highly addictive! Package contains 1 Thumb Chucks.