Star Trek had the trusty phaser. But, today, we have the stun gun. Many ordinary citizens carry stun guns and tasers to protect against personal attacks. These devices are designed to temporarily and immediately incapacitate a person. Stun guns and tasers generate a high-voltage. Stun-gun effectiveness varies depending on the particular gun model, the attacker's body size and his determination. It also depends on how the device is kept on the attacker. More info is available at FightBack247.com.