  We examine the bundle structure of the field of nowhere vanishing null vector
fields on a (time-oriented) Lorentzian manifold. Sections of what we refer to
as the null tangent, are by definition nowhere vanishing null vector fields. It
is shown that the set of nowhere vanishing null vector fields comes equipped
with a para-associative ternary partial product. Moreover, the null tangent
bundle is an example of a non-polynomial graded bundle.
