OK so here we go.
Should you purchase a stun device for personal protection? 83391 perpetrators in federal crimes prosecuted in 2004, bear in mind this is Federal Court only, State or local crimes are not included. That is reason enough for me to say Yes. Please refuse to be a victim!

The traditional stun gun has two protruding electrodes (positive and negative) which set up an electrical circuit between them so that current will pass between them when the stun gun is activated. The units do tend to produce two small burn marks where the current enters and leaves the body.

The early models are typically powered by nine volt alkaline batteries and have longer protruding electrodes. Some of us (including Poppajohn) prefer these. Most of the later models use three volt lithium camera batteries. This allows them to be constructed on a smaller frame. This also makes them a lot more handy and easier to carry. Along with that they typically use smaller electrodes that lay flat across the front of the stun gun, there is no evidence that this makes them any less effective than the larger more protruding electrodes, it does however contribute to their being handier and easier to carry.

Power from the batteries is passed to a coil (some use more than 1) where the voltage is increased to pretty much any level desired. The higher the voltage the more impressive the spark and the electrical noise when testing the unit (scary). Civilian stun guns use high voltage (up to a
million or more) at low wattage (7 to 14 watts) and miniscule amperage (around a milliamp or two) to temporarily disable an attacker for anywhere from a few seconds to several minutes relatively harmlessly.

These weapons work therefore by interfering with the communication signals within the nervous system of the target. Conventional stun systems primarily effect the sensory nervous system. Something like static on the communication lines between the brain and the body and in so doing they interfere with the human command and control systems. The effect is the muscles contract and relax at a very high rate.

So stun guns use high voltage and low amperage to temporarily disable an attacker for several minutes. The stun gun does not rely on pain for results though pain is a factor. The energy stored in the gun is dumped into the attacker's muscles causing them to do a great deal of work rapidly. This rapid work cycle instantly depletes the attacker's blood sugar by converting it to lactic acid. In short, he is unable to produce energy for his muscles, and his body is unable to function properly. The stun gun also interrupts the tiny neurological impulses that control and direct voluntary muscle movement . When the attacker's neuromuscular system is overwhelmed and controlled by the stun gun he loses his balance, you should then be prepared to catch your assailant and help him to the ground even though the attacker is touching you, the current will NOT pass to your body the circuit is entirely between the two ekectrode prongs of the stun gun! A small percentage of people with very high tolerance for electrical stimulation can fight through the effects and still offer considerable resistance.
Taser Weapons have called themselves EMD or Electro Muscular Disruption weapons specifically the Advanced Air Taser M18, M18L and C-2 tasers use a more powerful 18 to 26 Watt electrical signal to completely override the central nervous system and directly control the skeletal muscles. This EMD effect causes an uncontrollable contraction of the muscle tissue, allowing the Air Taser M18 and M18L or M-Series to physically debilitate a target regardless of pain tolerance or mental focus. The ADVANCED TASER M18, M18L and C-2 are this type of weapon -- specifically designed to stop even the most elite, aggressive, focused combatants. Rather than simply interfering with communication between the brain and muscles, the TASER M18, M18L and C-2 Tasers systems directly tell the muscles what to do: which is contract uncontrollably until the target is completely exhausted and most likely in the fetal position on the ground.

Some stun guns are built to resemble something other than a stun gun such as a cell phone or a flashlight or some other unique design which gives you a tactical advantage because since it looks like a harmless cell phone or what ever, it will be easy to surprise an attacker. Remember, the purpose of a taser gun or a stun gun, and all other non-lethal self defense products, is to give you time to escape. Use the stun gun, then head for safety. Don't stand around checking out the slobbering mook on the ground, clear the area.
Poppajohn has some amazing special prices on Air Taser M18 and M18L Guns available for a short time.

Air Taser M18

Also very competitive deals on the C-2

Self Defense Taser

stun guns / international

Always carry personal protection, be aware and have a plan!