What this luminous stone can offer you is that it is eco-friendly, safe and will not affect the health of aquatic life. Even if it is soaked in water for a long time, it will not lose its color and will not be deformed. With enough sunlight or light, these stones can achieve a good glow in the dark and last about 5 to 8 hours. Stone is made of non-radioactive resin, which is eco-friendly and does no harm to human body. The length of the product is 1.3cm, the width is 0.9cm. These stones can be used to create a beautiful and somewhat romantic path, aquarium or garden. This luminous stone can be carried around conveniently because of its mini size and light weight. Item Name: Luminous Stone Material: Resin Features: Multiple Colors, Luminous, Beautiful Size Details: 1.3cm x 0.9cm/0.51" x 0.35" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. The quantity is about 200pcs, due to manual calculation, the quantity might has 1-5pcs more or less, hope you can understand, thank you. Package Includes: 200 x Luminous Stone