Fibre Optic UV Sideglow and Hi-Brite LightsourceThis package incorporates our safe plastic UV reactive sideglow with 2 meters of 100 strands and one of our Hi Brite LED Lightsources to illuminate the strands for a calming visual and tactile experience. Use with a UV light to make the strands glow as well as twinkle. The Hi Brite Lightsource is passive+, it is designed to offer a superb passive experience. The length of the sideglow is shown in the product title.