What is "hypno-disc"

Hypno-Disc was a contestant entry in the Robot Wars TV series, and was one of the first robots to use the kinetic flywheel weapon — a highly damaging weapon that succeeded in heavily damaging and destroying a great many robots. Hypno-Disc's design, however, was somewhat basic, and its high ground clearance made it an easy target for robots armed with flipping weapons, such as Chaos 2. Hypno-Disc was the creation of the Rose family — twin brothers Derek and David, and their father Ken. It was the first competitor robot recreated in toy form when the Robot Wars pullback toys were released.