A hand-held air horn from the RAM Defense personal-safety range. Pressing the button releases compressed gas through the horn and gives a very loud blast that carries a long way, which can be used to call for help, scare off an attacker or an animal, or signal to others on a boat, at a sports event or in the veld. It needs no batteries and works immediately. Hold it away from your own and other people's ears when sounding it, keep it out of the sun and away from heat, and do not puncture the can. We could not find the volume of gas or the sound level for this exact horn, so check the label.