Twin-linked Macro-Accelerator Cannons mounted on the Astraeus Super-Heavy Tank.
The Macro-Accelerator Cannon is a large kinetic weapon used by the Primaris Space Marines' Astraeus Super-Heavy Grav Tank as its primary armament.
The Macro-Accelerator Cannon is actually a complex mass driver that uses a potent electromagentic field to accelerate a barrage of high caliber ferro-carbide slugs to extremely high speeds. Usually twin-linked, these weapons unleash an onslaught against which even enemy heavy armour cannot stand.