Annihilation plants or annie-plants power virtually everything that Schlockiverse civilization builds, from powersuits and handguns all the way up to battleplates and cities. They appear as teal spheres, often bulging out of the surface of whatever they power. An annie-plant's size varies in direct proportion to its neutronium capacity and power output, so a warship, tugboat, or other heavy lifter would have more and larger annie-plants than a yacht or liner of the same tonnage. Annie-plants can be scaled up to the multi-kilometer-diameter monsters found on Fleetmind ships, and down to the golf-ball-sized orbs on the newest plasgun models.
They are extremely tough, but if breached the neutronium inside explodes violently out the hole, creating a distinctive skoom sound. Annie-plants have elaborate gravy systems for keeping the volatile fuel confined. They also use gravitics to convert the neutronium into energy without using antineutronium, but the process is incomprehensible to anyone who does not have an advanced degree in each of several fields. Despite this complexity, annie-plants can be built in any good fabber.
Annie-plants can be used as munitions, by having the plant convert a great deal of its fuel all at once. Such total-conversion warheads are useful since their output can be controlled, by only annihilating part of their neutronium and letting the rest evaporate, which is much less energetic. This also means that on the safety-when-damaged scale, neutronium munitions fall somewhere between nukes and antimatter, since a damaged AM warhead goes off and a nuke is simply ruined.
Annie-plants make extensive use of post-transuranic alloys, which are energy-intensive to make and difficult to shape. A set of warship-grade annie-plants is worth more than the whole rest of the ship.