Ilyever 10 Pack Lights-up Fiber Optic Led Hair Lights Flashing Alternating Multicolor Hair Barrette Clip Braid - Party Supplies Package Contents:set of 10,batteries included and installed. Easy and quick to wear led light under the hair and easy to hide but can glow with many rainbow colors,Get noticed at bars, nightclubs, raves, proms, nighttime parties,or Burning Man. Uses two CR1220 replaceable batteries(included),you can get them at most drug, electronic, or hardware stores. Great for any nighttime event - rave party, prom, holidays, parties, nightlife, concerts, raves, festivals, weddings,great events.