The Sten (or Sten gun) was a family of British 9 mm submachine guns used extensively by British and Commonwealth forces throughout World War II and the Korean War. They were notable for having a simple design and very low production cost making them effective insurgency weapons for resistance groups.
The Sten Mk III was the second most produced mark after the Mark II. With its simple design, the Mark III was quicker and cheaper to build than the Mk II. The main difference between the two being the unification of the receiver, ejection port, and barrel shroud which extended farther up the barrel.