Remember that anything you use on a human for self defense (including the "kick in the nuts") can cause death. As a Police Officer I get to carry & use a assortment of items on "live" subjects that I need to really try to keep "live" if possible. I have used pepper spray dozens of times & it is real good But NOT the "end all" , any "hand to hand" tactics are better than nothing but you can get hurt really quick , running shoes are great but not always a option , cell phones out , by the time we get there someone is laying in a puddle , nix the knife ,risk to high for death , tasers & stun guns are to "maybe" , so what is my vote for? A 8 oz lead flat slap !! Not legal in everywhere so check , I have seen them use many times & EVERY time they worked !! Never jam , fail to open or lock , no delay for effect like sprays , I carry one as my "last ditch , on the ground , getting my ass kicked" backup. Understand that a slap CAN cause death if misused , and if you strike with the thin edge WILL make a nasty cut , but make NO MISTAKE about it , when the fight gets close and you have no choice , a slap to the head will spell "LIGHTS OUT" for even the toughest , drug crazied nut you can find , I have seen it , thats why I am sold. Just my 2cents worth & GOOD LUCK.