doppel is a wristband shown to reduce stress and increase focus - within moments.It works by creating a silent vibration on the inside of your wrist which feels like the ‘lub-dub' of a heartbeat. doppel's natural, psychological effect works in a similar way to music - slower rhythms are calming, and faster rhythms help you feel focused.Create, save and sync your personalized rhythms using the doppel app, then control the wristband with touch controls.Results showing doppel's calming effect have been published in the peer-reviewed journal Nature Scientific Reports.