A muti-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.
The explosive weapon was initially suggested by Seven of Nine to Captain Kathryn Janeway, to be used as a biomolecular warhead with which to disperse Borg nanoprobes, as a means by which to combat Species 8472. The mine would be loaded with fifty trillion altered nanoprobes, and send a shockwave which would disperse the nanoprobes over a radius of five lightyears.
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 Voyager's photon torpedoes as a delivery system instead.