Hypno-Disc was the first UK competitor robot to be turned into a pullback. It featured the horizontal flywheel of the real robot, activated by moving the pullback forward/back, as the front wheels axle connects to the flywheel. The rear armour was interchangeable, allowing the user to attach the spiky rear end of the Series 4 iteration (without the srimech), or the plain armour of the Series 3 version, this armour also featured the srimech. Underneath the armour plates was a small representation of Hypno-Disc's innards.