Material: Plastic Size of Star: Approx. 46mm x 46mm Color: Light Blue Color in the Dark: Blue/Green Quantity per pack: 100 pcs Phosphors radiate visible light after being energized. This means you have to expose the items to light for a while before they will glow in the dark. Phosphors then slowly release their stored energy over time. As they release the energy, they emit small amounts of light, which we see as an object glowing. Please take note of above for the item to work.