These lights are rechargeable and have all of the lighting mechanisms inside the cork. No batteries are needed.  Gently lift up beige cork from light mechanism to expose USB plug, then insert into USB charging  hub. Similar to charging cell phone. Do not twist cork or pull on wires. After 20 minutes, reattach cork to light and place inside bottle opening.  Charge lasts 8 to 10 hours. The clear twisting mechanism at the bottom of white cork light will turn the device on and off when ready to use.   All bottle lights are hand painted with acrylic or oil paint.