If you sometimes feel nervous while running by yourself outdoors, you’re not alone. The SaferRun Ripcord Siren Personal Alarm, coming to market in February 2020, was built to help you exercise with a greater sense of security. When you pull a tab, the thumb-size alarm emits a 120 db sound—as loud as an ambulance siren. Created by a female-led design team, the device is lightweight, easily fits in a small pocket and costs $19.99. —Madeleine Carlisle
Correction, Nov. 25
The original version of this story misstated how many decibels the Nathan Spots' SaferRun Ripcord Siren Personal Alarm emits. It is 120 db, not 125 db.