100 Pcs Luminous Cobblestones Pebbles Stones Glow in The Dark for Aquarium Fish Tank Decorations, Fantastic Garden or Yard Mixed Color Material: Photoluminescent pigment + resin Line a walkway, edge a flower bed or fill a planter with these unique acrylic pebbles After being exposed to daylight, these pebbles glow in the dark Glow lasts approximately two to three hours after full sun exposure warning! Pkg include:100 Man-made Glow in the Dark Pebbles Stone with a stylus