This weapon consumes hiperium to shoot, with a low fire rate. It creates a gravitational bullet that when hits its target causes average AoE damage with Penetration (but no fire). When this bullet impacts an enemy, it removes some momentum on the enemy ship and increases the weight of everything in the area for a few seconds (basically, it slows down the enemy ship for a few seconds).
Every time you shoot this weapon, it causes a E.M.P. effect in adjacent tiles, so you must put this weapon in a smart position to prevent complications on your ship.
There could be also a Gravitational Missile with a similar effect.