Defiant Class

 

General description
Unlike other Starfleet ships, the Defiant is primarily designed for military purposes. It was developed in order to oppose a Borg invasion. The ship has novel phaser arrays and quantum torpedo launchers. While further ships of this class have been built in the meantime, the USS Defiant which is probably the only one with a Romulan cloaking device is still in experimental status.
Known ships
USS Defiant NX-74205
USS Valiant NCC-74210
Annotations
1) It can be supposed that the Dominion threat was the incentive to continue production of the Defiant class, although the prototype ship does not meet Starfleet standards.
2) The Defiant is believed to have landing struts, however, they have not been shown yet. It is questionable if the ship is capable of atmospheric flight and landing on planets, since this would have been an option in several episodes. So it is suggested that the relatively small Defiant was designed to use the shuttlebays in starbases.
Class specifications
Escort
Length: 120-170m
Deck count: 6-8
Max. speed: Warp 9.8
Crew complement: 47
First commissioned in 2370

Information source:
Bernd Schneider's Star Trek Website