I LOVED my Scream Box! It was an audio grenade. A few of the first volunteers in country had been mugged. So, everyone got a personal safety device after that. I never needed it, but I used the hell out of it, and wow was it loud! One day, during training, I pulled the pin and tossed it into one of the other classrooms. Joy.

I had so much fun that I bought one a few years ago. Same good times.

I really have no idea how effective such devices are at deterring criminals.