Phosphorescent Pebbles: These pebbles absorb and store energy from the sun or other light sources. They automatically glow in the dark. After being charged with sunlight, the stones can glow in the dark for 1-2 hours. The stones are green by day and blue by night. If the stones no longer sparkle enough, let them shine again. Safe and durable: the main material of the pebbles is resin. Non-toxic, non-radioactive and odorless. The product is harmless to humans, fish, birds and plants. The stones have been beautifully finished and polished so that they have no sharp edges. Ideal for outdoor, aquarium, garden, screw jar, walkway and yard. Applications- Light stones can be used as decoration for: walkway, cycle path, flowerbed, flowerpot, aquarium, garden. Use these stones to create your own decoration for vase, fish tank, garden, pool, pond, bar, home, lawn, birdbath, flowerpot, patio, etc. Easy to use - The pebbles will last longer Place in the sun or exposed to artificial light for 4 hours, then placed along the walkway. At night, your garden will look beautiful and beautiful with these light stones. Note: For better lighting effect, please place these pebbles next to each other. It is best to place 10 or more stones close together to make them shine brighter at night. According to laboratory tests, a single stone can be used for about 1 year. 3 hours. If 5-10 stones are close together, they shine for about 5 hours and are brighter than a single stone. If 100 stones are close to each other, they glow for about 7 hours and are very bright at night.