This drum contains a bank of 6 capacitors in a circle formation, centered around an electron charge pack (ECP).
The unique feature of this "laser assault rifle" is the addition of a "drum," which gives this weapon its unique look, high rate of fire, and name.
A precursor to the Gatling laser, the gun was designed to mimic a famous gun design and invoke in buyers the same rapid delivery of ordnance but instead with lasers.