Built-in rechargeable battery,no need AAA batteries,saving cost. Recharged by all USB devices (like USB adapter,power bank) with charging cable included. Elegant Shell in nbsp; with magnet inside,easy to install,tool-free,2 ways WAY 1: Free adsorption on any metalwork surface eg refrigerator,barbecue or inside the gun,WAY 2: Stick on any non-ironwork,clean surfaces with the included metal strip and double-sided tape. Portable and free exchange places according to your wishes. 2 lighting mode: Switch to G : Automatically turns on when human movements are detected in the dark or at night,automatic shutdown after 20s if no movement is triggered again (Do not not light up in an environment very bright or during the day); Switch to On : permanently lit,can also be used as a flashlight or emergency light. PIR Motion Sensing Human movements activate,AUTO Light On / Off. Smart security lighting perfect for cupboards,hallways,verandas,wine racks,bathrooms,hallways,anywhere you need lights.