The Object 490B Belka is an alternative design proposed for the Object 490 main battle tank after the decision in 1984 to use a 152mm smoothbore gun on the future Soviet MBTs instead of the 125mm smoothbore gun.

The Object 490B vastly differed from the original Object 490A design had an extremely sloped steel frontal armor instead of composite armor and four sets of tracks.

The design had a two-man crew placed at the rear of the vehicle with the main gun and its ammunition in a separate compartment in front of them, while its two engines and fuel tank was placed at the front.

The placement of the crew at the rear most part of the vehicle greatly increased the crew's survivability and made the use of composite armor unnecessary, given that the tank's other components in front would be sufficient to stop any penetrating projectiles from getting into the crew compartment.

The tank's four sets of tracks was intended to allow the vehicle to still be mobile even if the front tracks were damaged by mines or enemy fire.

The design never went past the scale model mock-up stage due to the introduction of the Object 299's Universal Combat Platform concept of vehicles in the late 1980s.