VIU-55 Munja (en: Lightning) is a combat engineering vehicle produced by Serbia. VTI has done the conceptual design of the Munja general-purpose engineer vehicle and the Čačak-based Overhaul Depot has built the vehicle. The main idea was converting the T-55 tank, using its main structure and subsystems and adding new components, equipment and devices to create a vehicle for entirely different purposes. Good terrain negotiating ability and ballistic protection of T-55 tank were retained, while engineer equipment and armament were refitted. It is the first armoured vehicle for the engineer corps outfitted with special purpose engineer equipment and respectable armament, belonging to the most modern designs of this kind. It is designed to negotiate natural and man-made obstacles, blocking, fo