Feature: 1. Principle Of Use: Put the dice under sunlight or strong lights to get the ideal luminous effect. The luminous effect also depends on the brightness of the use environment. The darker the environment, the better the luminous effect. 2. Permanent Luminous Performance: If the dice fully absorbs the light energy, it can continue to emit light in the dark for 2‑3 hours; when the energy is exhausted, it can emit light again by repeatedly absorbing the energy. 3. Safe To Use: Exquisite workmanship, attention to details, can be great decoration, smooth surface and mellow corner, will not scratch skin, can be used with confidence. 4. Multiple Applicable Scenarios: Light weight and in small size, easy to store and carry, suitable for bar, KTV, Christmas party, family gathering, board game, etc. 5. Acrylic Material: Luminous dice adopts excellent acrylic material, eco friendly and odorless, anti impact, firm and sturdy, stable and durable for use. Specification: Item Type: Luminous Dice Material: Acrylic Size: Approx. 14mm / 0.6in. Package List: 18 x Dice Note: Please allow slight error due to manual measurement. Thanks for your understanding.