SOUND REACTIVELed light change with music drops, super cool and great for Music Festivals, Concerts, Raves, Costume Parties, KTV, Bars,Halloween,Christmas, Indoor & outdoor. WARM TIP: there is a Slide Button for 2 sensitivity levels adjustment for choosing Normal or Lound environment, if you find your light up glasses not responsive to sound,pls try to adjust the button. USB RECHARGEABLE LED shutter shades work about 8Hours under full charged in a high-energy noisy environment, no need to waste money buying expensive button cell batteries. High cost performance & environment friendly 2 COLORS TO CHOOSEBlack & White color available, top notch quality. want more products for party. WEAR ITAs seen on the Today Show, become a eye catcher. Prefect for the night club, raves, music festivals, concert and other event. FLASHING DECORATION Easy to see through without obstructing your vision,also as a cool outfit while wearing them during holiday. Package include: 1x shutter glasses, 1x usb cable