A multi-kinetic neutronic mine was a weapon of mass destruction utilized by the Borg. With a yield of five million isotons, the mine had the capability of producing a shock wave over a radius of five light years, affecting entire star systems.
In 2374, Seven of Nine proposed using a multi-kinetic neutronic mine as a biomolecular warhead with which to disperse Borg nanoprobes, as a means by which to combat Species 8472. However, as the use of such a device would require a matter of weeks to replicate the necessary fifty trillion nanoprobes, and Captain Janeway was unwilling to utilize a weapon which could endanger innocent worlds, it was decided to use the USS Voyager's photon torpedoes as a delivery system instead. (VOY: "Scorpion, Part II")