The Son'a metaphasic collector, also refered to as the Injector, was a massive spacecraft designed by the Son'a for the specific purpose of harvesting metaphasic radiation from the rings of the planet Ba'ku. The collector was designed to launch an injector that would produce a cascading thermolitic reaction within the rings, allowing the collector to harvest the radiation that emanated from them. A major side effect of this process, however, was that the planet would be rendered uninhabitable for generations.
With the assistance of the Federation, the Son'a were able to finally deploy the collector in 2375. Fortunately, the collector was disabled moments before it could launch the injector when Jean-Luc Picard, Worf, and Subahdar Gallatin commandeered Ru'afo's flagship and deactivated the collector. However, Ahdar Ru'afo managed to transport aboard the collector shortly thereafter and raise its shields. Picard, nevertheless, managed to beam aboard by transporting between the shield generators and reactivate the collector's self-destruct sequence. Picard was beamed away seconds later by the USS Enterprise-E, but Ru'afo was killed when the collector exploded. (Star Trek: Insurrection)
The CGI model of the Son'a collector was designed by John Eaves; the computer-generated model was built by Blue Sky/VIFX. It was intended to be 5000 feet (1524 meters) long, but Eaves noted that the scaling for the vessel was problematic throughout the movie. (Blog entry)
The Star Trek Customizable Card Game gives its name as Injector Assembly One.