Optronic Data Core
The Optronic Data Core was a piece of technology in service with Starfleet during the mid 2370's. After the Hirogen and the Voyager Crew called a cease-fire following the deadly World War 2 Battle of St Clair war games the Voyager crew gave the Hirogen an Optronic Data Core as a trophy.
Captain Kathryn Janeway said that the Hirogen could use it to create a new future for the Hirogen. Instead of dispersed across the quadrant the Hirogen could re-form their civilisation and instead of hunting the Optronic Data Core could be used to create holodeck technology; and thus creating an unlimited supply of prey.
The Hirogen accepted the trophy and they evacuated Voyager.