Drawing inspiration from the British STEN gun, the M3 was developed as a high-speed, low-cost substitute for the Thompson family of submachine guns. While lacking the aesthetic charm of the Thompson, the M3 was a serviceable weapon, and would be America's go-to SMG through World War II and following conflicts. Blade front and peep rear sights, model nomenclature and Guide Lamp markings on the left side of the magazine well, oiler slot (empty) on the left side of the trigger group cover, the early pattern cocking handle on the right, the combination dust cover and safety on top and a two-position telescoping buttstock. A set of "P" and "flaming bomb" proofs are present on the receiver and bolt, and British proofhouse markings are present on the barrel. A loading tool is included.