The Verge reviews Pebblebee's Halo, a $59.99 Bluetooth tracker that combines lost-item tracking with personal safety features including a 130dB siren and LED strobe, which the reviewer found useful as a legal alternative to pepper spray in Los Angeles.

The Verge

I live in a part of Los Angeles where I feel safer bringing pepper spray on walks. The problem is, I don't always remember to bring it with me, and it's not legal to carry it everywhere I go. Pebblebee's $59.99 Halo Bluetooth tracker surprised me by being a suitable replacement because it doubles as a siren-equipped personal safety device, and I can bring it anywhere.
A quick pull of its cap triggers a bunch of safety features: Its 130dB siren will sound, its LEDs will strobe, and it will automa