The W3901 is an electronic attack pod developed for the U1. Instead of containing a wide variety of electronics, it uses a radiation induced EMP device to damage shields and electronics. The relatively wide spread of radio and gamma waves helps ensure a hit by blanketing an area in energy, though that radiation generally isn't powerful enough to blow a hole in something it is more than enough to destroy electronics even through a faraday cage. The blanket-nature of the EMP device and modern shield's systems insistence on blocking all forms of attack also make the weapon very effective for its size in attacking shield systems.
The pods require power and targeting from their parent craft. They are designed to work in pairs, and can steer their radiation beam 190 degrees off from any emitter. Each pod has two emitters, one on the front the other on the rear and the pods work best when multiple beams can converge on a target.