A-20, was specified with 20 mm of armor, a 45 mm gun, and the new Model V-2 engine, using less-flammable diesel fuel in a V12 configuration. It also had an 8×6-wheel convertible drive similar to the BT tank's 8×2, which allowed it to run on wheels without caterpillar track. A-20 also incorporated previous research (BT-IS and BT-SW-2 projects) into sloped armor.