A Yak-2 was modified with the so called KABB device, an acronym for combined artillery-bomb battery.

The device was conceived by Mozharovskov and Venevidov, and consisted of a ventral pod with two ShWAK 20 mm gun and two ShKAS 7,62 mm machine guns. All these weapons could be inclined downward in flight from the cockpit and fire obliquely at different angles .

The purpose was the possibility to attack a ground target contemporarily with guns and bombs.

The plane differed from standard Yak-2s for:

• the gun pod;
• the glazed nose;
• the new aiming device;
• the remotion of the rear seat to allow access to the ammunition bay; this transformed the plane into a single-seater; the rear glazed part looks unaltered.