Scientific UV beads are extremely sensitive to natural light and change color dramatically from white to various colors when exposed to sunlight or even on an overcast day. They need to be put under the ultraviolet first until they turn into different colors. The stronger the ultraviolet, the darker the color. Fun for jewelry making, DIY bracelet or necklace. And great for teaching UV awareness, UV light experiment and lesson activities. Good for arts and crafts, not for children under 3 years old.Features- Color: As shown.- Material: Plastic.- Size: 6x9mm / 0.2x0.4inch.- Amazing Beads Color Magically Changing UV Reactive Beads for Jewelry Making.- Package comes with 6x9mm 250pcs pony clear beads color changing in the sun.- Appear translucent at first but bring them out into the light and watch them magically change from clear to colorful.- plastic pony beads color changing in the sun for DIY bracelet or necklace, amazing gift.- Fun for jewelry making, and great for teaching UV awareness