This is technically sold as a keychain, but we see much more creative uses for it. The rapidly flashing multi-color LEDs look cool enough for you to add a string to wear this around your neck, creating a diffused strobing effect, but swing it around using the keychain loop or your own string, and make giant trails of bright streaking color. Just use different lengths of string and create different diameter circles of light! 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 long-lasting included nonreplaceable batteries. The ball is about 1.2" diameter.