SOUND REACTIVE LED light changes with music beats, super cool and perfect for music festivals, concerts, raves, costume parties, karaoke, bars, Halloween, Christmas, and both indoor & outdoor events. WARM TIP: There is a slide button for adjusting sensitivity levels for either normal or loud environments. If your light-up glasses seem unresponsive to sound, please try adjusting the button. USB RECHARGEABLE These stylish LED shutter shades offer approximately 8 hours of use when fully charged in a high-energy noisy environment, eliminating the need to purchase expensive replacement batteries. High cost performance & environmentally friendly. 2 COLORS TO CHOOSE FROM Available in black and white, featuring top-notch quality. For more party products, visit the store. WEAR IT As seen on popular shows, become the center of attention. Ideal for nightclubs, raves, music festivals, concerts, and other events. FLASHING DECORATION Easy to see through without obstructing your vision, these are also a fashionable accessory during holidays. Package includes: 1x shutter glasses, 1x USB cable.