What defines a Wheel device in pyrotechnics?

A Wheel device in pyrotechnics is characterized by its multiple components that rotate around a central axis. This design allows the wheel to produce a variety of visual effects, including sparks, flames, and sometimes colored bursts, as the components move. The rotational mechanism is key, as it enables the wheel to create dynamic displays that can capture the audience's attention through movement and the variety of effects produced.

The other options do not encapsulate the definition of a Wheel device accurately. A device producing smoke effects is not specific to the rotating design that defines a Wheel. A stationary device that shoots flames upward describes a different type of pyrotechnic device, one that lacks the rotational aspect. Lastly, a device that emits sound effects without visual components does not align with the primary function of a Wheel, which is to provide visual pyrotechnic displays through its rotating components.