The B'rel class not only remained in service well into the 24th century but also inspired a larger variation, the K'Vort-class. The B’relclass, first developed in 2270, is the second known Bird-of-Prey operated by the Klingon Empire, it builds directly on the successful design on the earlier Birds-of-Prey but includes ideas and technology taken from Romulan designs obtained in the short lived Klingon- Romulan alliance of the 23rd century, most notably a cloaking device. Variations of the B'rel class include the K'Vort-class and the D12-class bird-of-preys. They were classified as a class 1 vessel. ( TNG episode: ' Rascals' Decipher RPG module: Starships CCG: 'Rules of Acquisition') By the 24th century, these vessels were considered surplus, and were often sold or traded to other powers. The B'rel-class (also known as the K22B-class) was a type of Klingon bird-of-prey scout starship in Imperial Defense Force service in the 23rd century.
