The Kanohi Olmak was the Kanohi Mask of Dimensional Gates. It allowed its user to open portals to other dimensions and either pass through them himself or force others into them.
The Kanohi Olmak was the Mask of Dimensional Gates. It could be used to transport a target into another dimension or to another location within this one.
The Order of Mata Nui suspected that the Brotherhood of Makuta had access to a more powerful version of the Kanohi Olmak, or something similar, which they used to transport the island of Destral from place to place.
The Kanohi Olmak was the Mask of Dimensionak Gates. It had the power to open gateways to interdimensional space.
The Kanohi Olmak was the Mask of Dimensional Gates. On Destral, Tridax had possession of one of only two known to be in existence [including or excluding Brutaka's?]. The mask could reach other places not only in the same dimension, but other realities as well.
The Kanohi Olmak, the Great Mask of Dimensional Gates, was worn by Brutaka. It allowed its user to open portals to inter-dimensional space.
Brutaka got his Olmak from the Order of Mata Nui.
Artakha likely realized how powerful the Olmak was and so limited the number produced.