The 300,000 volt curved model of the Stunmaster® stun gun has the power to back someone up. Just the crackle of the high voltage stun gun when fired will get an attackers attention and probable make them think twice. Just in case you have to use it on your attacker a 1 to 2 second jolt and you have ruined his day. The high voltage of the stun gun causes muscle spasms and interrupts the attackers neuromuscular system, overwhelming it and incapacitating the attacker. The SM-300C model has a "Lifetime" warranty and uses two (2) 9 volt batteries (not included).