Condition: 100% Brand New Item Type: Fluorescent Sand Material: Rare Earth Aluminate Service Life: 15 years Weight: 100 g / 3.5 oz(approx.) Usage: Sunlight or bright light shines for 20 minutes, then you can bring it to the dark and start to shine Description: 1. Q: received luminous particles will not emit light, is it invalid? Answer: Fluorescent particles are light-storage products. The principle is that light can only be emitted by absorbing light source. The luminescence lasts for 2-8 hours each time, and the first 1-2 hours are the highlight period and then continue to emit light.The received product does not emit light because it does not absorb light in the logistics process.Just get some sunlight or a light and it will shine again. 2. Q: Why do I get the sun during the day, but it doesn't light up at night? Answer: because the principle of fluorescent is edge absorbs light edge to give off light, that is to say, also begin to give out light in the process that accumulates light, if absorbed light during the day, but passed dusk time, had the highlight period of fluorescent, can see slightly weak light only so, but at this moment turn on the light to shine again can see very bright. 3. Q: What color is the brightest fluorescent particles? Answer: yellow green, blue green, sky blue, three basic color Package List 1 x Fluorescent Sand (100g) 1Wide application, suitable for clothing, safety instructions, manicure, body painting, wishing bottles, DIY and other purposes. 2Does not contain all radioactive substances, does not belong to the combustible explosive substance, does not contain harmful elements, safe to the human body 3Fluorescent particles, long lasting, can be used repeatedly, life up to 15 years. 4Sunlight or bright light shines for 20 minutes, then you can bring it to the dark and start to shine. 5Suitable for all kinds of DIY decoration or handicrafts, such as decorate the road, walkway, gardens, wishing bottle, and so on.