Modernization of respectively T-55 and T-55A with new "Volna" fire control system, 9K116-1 "Bastion" ATGM system with new 1K13 BOM guidance device/sight, improved "Tsiklon-M1" gun stabilization system and TShSM-32PV sights, V-55U engine, improved suspension and RMSh tracks, increased armour, anti-mine, anti-napalm and improved anti-radiation protection and new R-173/173P radio set . Visual differences include a laser range-finder in an armoured box fitted over the main armament, side skirts, 81mm "Tucha" smoke grenade launchers, BDD turret brow armour and glacis appliqué, and rear RPG screens (only used rarely in Afghanistan).