The Serex class was a type of heavy frigate that saw service in the Romulan Star Navy during the 24th century. (Ship Recognition Manual, Volume 5: Starships of the Romulan Star Empire)
The V'del was a Serex-class vessel assigned to the V'korran Command Wing during the Dominion War. (The Dominion War Sourcebook: The Fires of Armageddon)