A ysalamiri cage mounted on a Mobile Defense Unit. The ysalamiri cage was an item discovered on Mobile Defense Units belonging to the Zann Consortium. The Consortium put these cages to use, each holding one ysalamir brought from Myrkr, to generate zones where the Force was nullified. This meant that users of the Force could not tap into their abilities within these zones. This provided the Consortium's troops with an edge when fighting against individuals who were Force-sensitive.
The sole instance of this in true canon occurred during the Theft on Coruscant. In terms of gameplay, the construction of ysalamiri cages is only possible when the Zann Consortium has control over Myrkr.