A group of mini-drones seeking out their targets.
Consisting of a small black sphere roughly the size of a large marble, a mini-drone explosive held a reservoir of two liquids that were harmless on their own; when mixed, however, the drone would spark with electricity briefly before detonating violently. However, a Jedi or other Force-sensitive of sufficient skill could use the Force to keep the two liquids from mixing and thus stop the explosives from detonating.
Capable of independent movement and rudimentary intelligence, these drones could be dropped covertly through openings, whereupon they would zip towards their targets, be it individuals, points in a structure, or otherwise. A deadly explosive on their own, a single mini-drone could kill a small clustered group of people, while a handful could act as a bomb.
Rackham Sear orchestrated an attack on the Jedi Temple, where he covertly infiltrated the temple's air ducts and released mini-drones through the vent grating; these drones, while only a few handfuls in number, proceeded to spread throughout the facility and wreak massive damage, putting the Jedi inhabitants into a state of emergency.