Item Description1. Glow lasts approximately two to three hours after full sun exposure2. After being exposed to daylight， these pebbles glow in the dark Line a walkway， edge a flower bed or fill a planter with these unique pebbles3. These are a flat marble size and are made of a poly resin material4. Great for Lighting Exterior Walkway LightingNOTE : Please let them receive sunlight for more than 3 days . Features1. Luminous and made from acrylic2. Pebbles are approx 2-3cm each3. Usable indoors， subject to light availability Package Includes1 x set (100 pcs) of pebbles stone in multi colors