The Apollo Neuro is a scientifically safe and sound wearable device. It works by improving your body's resilience to stress by training your nervous system to bounce back more quickly from the fight or flight mode. I use it to help with winding down before bed, sleep, waking up, and when I need to be in deep focus mode. It's worn on your ankle or wrist. I prefer the ankle and have to use the wrist strap for it to fit correctly. It feels like a little haptic or buzz on your ankle for a minute, and then your body gets used to it, and you don't feel it at all.