The set is made of both consoles plus the Tal Shiar Adapted Borg Warp Core that both ships come with.
Originally Posted by Wiki
Utilizing this Warp Core in conjunction with both of the consoles found on Tal Shiar Adapted vessels will result in additional Exotic Particle damage being dealt to targets of most offensive science abilities.
See it here and here. For example, particle damage is stuff like warp plasma or tractor beams.