The operation of the Steel City is bound to a unique rotary knob: While turning, several "steps" can be felt as "real" physical resistance. These are not analog in nature, but instead are generated through a magnetized liquid inside the knob's housing and can be programmed in realtime. The knob is programmed to adapt accordingly to every selected content and therefore enabling the experts from Primetals to focus on their visitors without ever taking their eyes off the presented stories.