Jach class

The Jach-class was a Klingon starship class, a cruiser vessel in service to various Great Houses of the Klingon Empire in the 2250s decade. 

Service history
Following roughly a century of relative peace, the Federation encountered Jach-class cruisers when the Starfleet starship USS Shenzhou, and its backup, was attacked by representatives of 26 Klingon Great Houses at the Battle of the Binary Stars on May 11, 2256. The battle had been instigated by the fanatic T'Kuvma to reunite the Empire by rallying its houses against a common foe. 

At some point, ships of the class were part of Federation-Klingon engagements involving vessels from different cultures and eras. 

Specifications
When the Klingon Empire was in disarray, ships of the Jach class were fielded by several Great Houses, rather than the Klingon Defense Force. The vessel's design was defined by a elongated primary hull, narrowing at both ends, flanked by comparatively large pylons or wings. 

Ships of the class were rated cruisers. During the Federation-Klingon War of 2256-2257, Jach-class starships were equipped with cloaking devices developed by the House of T'Kuvma.