An Entity receives a Stimulus. Let us guess that it sends back a Stimulus of a different type. Let us take the phone example. We can consider that it is an Entity which is able to receive or emit electromagnetic or acoustic stimuli. Nevertheless, if it is thrust into an isolated system, it will not do anything. In fact, it does nothing more than turning sound waves into electromagnetic waves and vice versa. This is a Stimuli converter.
We can also imagine an Entity of a special type made of several parts split up between different locations. This stays hypothetical, but this could give a remote transmitter-receiver able to receive Stimuli in a Place and to send them back in another. Perspectives given by such Entities are very interesting, as Stimuli relays from a container to another (refer to "StimuliDispatcher" section).