The superpartner of the right-handed neutrino provides an alternative
to the neutralino WIMP dark matter in supersymmetry.
We consider the case where this feebly interacting particle is
produced via the decay of the long-lived next-to-lightest charged sfermion.
After taking into account constraints such as dark matter relic
density or big-bang nucleosynthesis, we discuss the discovery propect
at future runs of the LHC notably through the charged track signatures.