Best weapon to carry for self defense that requires no license?

a can of three dollar wasp killer spray is the best and cheapest legal defense i know of .for the lack of knowing the brands Bee Bop works good . Shoots twenty feet and if you hit a person in the face with it they won't be able to see and will have trouble breathing and it can be bought in any grocery store .. and is legal to have in your possession anywhere . Stuff works better than pepper spray and has more range