What is unique about an easement in gross?

An easement in gross is defined by its unique feature of not requiring a dominant tenement. This means that the easement is attached to an individual or entity rather than to a specific piece of land. In practical terms, the holder of the easement has the right to use a portion of another person's property without the need for another property to benefit from that easement.

This characteristic differentiates easements in gross from other types of easements, such as those appurtenant, which are directly linked to the ownership of a particular parcel of land (the dominant tenement) that benefits from the easement across another's property (the servient tenement). The other options listed do not accurately capture the essence of what makes an easement in gross distinct.