Introducing the Spring M40 Submachine Gun Airsoft Gun. Used by the German’s in World War II now you can own the airsoft version of this fantastic submachine gun. The M40 features a folding stock that will swing underneath the gun allowing for a more compact gun. The hop-up will allow the BBs to travel further with more accuracy and the R.I.S. located above the gun will let you customize the gun with any attachment. Get the Spring M40 Submachine Gun Airsoft Gun and join the action!