Subsonic Repeater

The Subsonic Repeater is a close-range SMG that grants great footspeed when equipped. It has a very high rate of fire, and thus remains the fastest firing weapon on Cybertron.

Transformers: Fall of Cybertron
Subsonic Repeaters were used during the later days of the Great War between the Autobots and Decepticons. They replaced the Ion blasters used earlier, and are commonly used by Infiltrators. Perceptor, Wheeljack, Jazz, and Cliffjumper all used this weapon during a skirmish in the Sea of Rust.

Transformers: Rise of the Dark Spark
The Subsonic Repeater is available in escalation along with all the other weapons from Fall of Cybertron.