 It has a longer barrel with three vent ports.This machine pistol has a horizontal rail in front of the trigger guard through which a spare 16 or 20 round magazine can be attached and be used as a fore-grip for better control during full automatic firing.During the 1990s, the Russian Stechkin APS was once again put into service, as a weapon for VIP bodyguards and for anti-terrorist hostage rescue teams that needed the capability for full automatic fire in emergencies.