The tank was based on a lengthened T-80U hull, with an extra pair of road wheels and a brand new turret. It appeared to have had very thick front armour and new-generation "Kaktus" explosive reactive armour on the hull and turret. The turret had a very large, box-shaped turret bustle instead of the traditional dome shape of previous Soviet and Russian main battle tanks. According to Russian reports, the Black Eagle design had abandoned the carousel-style autoloader in the fighting compartment for an autoloader mounted in the large western-style turret bustle, which incorporates a blow-out armoured ammunition compartment for crew safety, like the U.S. M1 Abrams, the German Leopard 2, British Challenger 2, French Leclerc and several other modern western tanks. The prototype had a 125 mm tank gun, but it was stated that it may have accommodated a larger 152 mm gun (compared to the 120 and 125 mm-calibre guns of main battle tanks in service). There was debate about whether the Black Eagle would incorporate the Drozd or Arena (countermeasure).