Hydrogen stabiliser
From Tardis Wiki, the free Doctor Who reference
Hydrogen stabilisers were an apparent technology used by the Skelloids to regulate the absorption of hydrogen through their gill-plates. Banto Zame, posing as the Doctor, seemingly foiled an invasion of the Generios system by the Skelloids by exploiting their life cycle's reliance, using his psychic screwdriver to invert the core of their hydrogen stabilisers. In reality, the Skelloid invasion was nothing but a mere holographic illusion created by him. (AUDIO: The One Doctor)
It is unclear whether or not the Skelloids existed beyond Banto's illusion.
