The probes travel at a speed of 135 feet per second (41 meters per second) with a maximum reach of 15 feet (4.5m). When the probes attach to the attacker's clothes or skin, an electric shock passes between them, through the body, incapacitating the assailant's neuromuscular system. The attacker will lose all control and coordination. The taser will continue to apply the electrical charge in an auto-timed sequence of an initial charge of several seconds followed by many short bursts. This prevents the assailant from recovering from the initial shock and removing the probes. During this event the user can abandon the taser on the ground and escape.
Because the charge passes through the part of the body that is directly located between the two probes, for maximum effectiveness the taser probes should land with at least a 6-inch (15cm) spread between them. The closer the attacker is to the taser when it is fired, the closer together the probes will land. Therefore the optimum distance to fire a taser is between 7-10 feet (2.2-3m) to give the probes a chance to spread about 16 inches (41cm) to deliver the greatest possible shock to the body.
Tasers cannot permanently harm the muscles, nerves or heart, nor will it interfere with a pacemaker. The current of 0.3 joules is far below the 10-15 joules which marks the threshold, beyond which problems could occur. The affect of the taser is that the attacker will be dazed for several minutes, before fully recovering. Tasers can be used safely in water and will not cause electrocution. They can also be used in weather ranging from -20 to 160 degrees Fahrenheit (-29 to 71C), and will perform at any altitude.
A taser cartridge only holds one set of probes so once it is fired the spent taser cartridge must be replaced before it can fire more probes. However, if the user misses the target or if there is more than one assailant, the end of the taser can be used as a touch stun gun. By pressing the end of the taser against the attacker or his clothes and discharging it, an electric shock passes into the attacker, incapacitating him in the same way previously described. Visit here for more.