This is technically sold as a necklace, but we see much more creative uses for it. The rapidly flashing multi-color LEDs look cool enough when you wear this around your neck, creating a diffused strobing effect, but swing it using the included neon colored lanyard, and make giant trails of bright streaking color. The lanyard is long enough to make a 2-foot diameter circle of light, but you can even change to a longer string yourself and create even larger circles. Tiny enough to slip into your jeans pocket when you head out to the clubs, but so cool when you pull it out while dancing. Uses 3 replaceable AG3 batteries (included). The ball is about 1.2" diameter.