These LED lights are super easy to use, just pull out the Insulation film. To turn it off, insert the film back. Nice for warm and happy festive decoration. Use for mixed media projects, shadow boxes, parties, plant pots, centerpieces and more. Perfect for weddings, birthdays, Christmas, dinner parties, performances, Halloween and other celebrating occasions. Battery powered, but not replaceable. Light lasts more than 24 hours and up to 5 days. The ball is approximately 1.7cm in diameter. The package includes 10 ball lights in cool white.