The perfect accessory for concerts/parties or just making sure you can be seen in dark places. Acrylic Light Bulb flashes Red/Blue/Green slowly, then flashes that combo fast a few times and back to the slow cycle again. SEE VIDEO BELOW FOR DEMONSTRATION. Leather necklace is about 30" long. Light Bulb measures 2" long by 1" wide. Batteries are included and can be replaced when they run out.