Theta-band device
A theta-band device was a type of theta-band subspace delivery system that could be used to create a metagenic weapon.
Captain Jean-Luc Picard was one of three Starfleet captains who had extensive knowledge of theta-band devices. In 2369, the Cardassians created a fake metagenic weapon in order to lure Picard into capture, based on their knowing of his extensive knowledge of theta-band devices. (TNG: "Chain Of Command, Part II")