To many people it would seem that there is no difference btween stun guns and tasers, except, of course that you need to be able to aim, at least a little bit, to use a taser.  Actually, there is a fundamental difference between the two classes of defense product and if has a profound impact on the effectness of both tasers and stun guns as self defense weapons. 

Stun Guns and Stun technology weapons work in the 7-14 Watt range.  They are designed to interfere with signals as they travel within the central nervous system and they primarily affect the bodies sensory nervous system. Essentially, they jam up the witing between the brain and the body.  The critical drawback of this technnolody is that there is a small percentage of people with a naturally high tolerance for electrical stimulation and they can through the effect of these systems based on 7-14 Watts.  Recently, this has become more of an issue with the use of drugs like PCP, which essentially render the users oblivious to pain and just about everything else.  The old Air tasers - like the Air taser 34000 series are stun weapons. The technology and the settings for these weapons haven't changed in the last 20 years.

The new breed of tasers  including the C2 and M18 devices, are different.  EMD/ EMC Electro- Muscular-Disruption /Electro-Muscular-Control technology devices don't just interfere with the central nervous system of the attacker they are used on.  EMC weapons use a more powerful technology operating in the 18-26 Watt range, to completely over-ride the central nervous system and directly control the skeletal muscles.  There is no possibility to fight through the effects of the new tasers, because they create involuntary and completely uncontrollable contractions of the muscles. This completely debilitates the attacker, regardless of what drugs they might have in their system and gives the person with a taser the chance to leave the scene and call the authorities.