This model of the Scorpion EVO3 S1 is a blowback-operated semi-auto in 9mm with a short 7.72" barrel. Open sights ride on an 11 Picatinny rail for mounting optics. It features a 1/2x28 threads hidden underneath the factory flash-hider, meaning users can fit either 1/2x28 or 18x1 accessories to the muzzle. Also added is a QD sling swivel pocket integrated into the rear sling attachment point. It not only has ambidextrous controls, its non-reciprocating charging handle is swappable and reach to the trigger is adjustable.