Nothing really prunes your friends like the Fox 40 Ecoblast Air Horn. Unlike many air horns that rely on one-time-use canisters, this puppy comes with a handy bike pump so you can keep the fun going until your arms get tired. At 120 dB, this ozone-free horn can be heard up to a mile away, making it an essential item for ship captains (it meets Coast Guard regulations), lacrosse coaches, and substitute teachers who need to fight back.
Ethan Wolff-Mann is the Gear editor of Supercompressor. He has been asked by police on three occasions to turn the volume down. Follow him on Twitter @ewolffmann.