TOOGOO(R) 100pc Purple Fish Tank Garden Parterre Decor Glow in the Dark Fluorescent Pebble Stone 1.7*2.4CM(Purple) Quantity:100pcs I like it very much since :It can decoration you Garden ,Fish Tank, let they looks so shining in the dark. Line a walkway, edge a flower bed or decor garden ,fish tank with these unique pebbles. Glow lasts approximately two to three hours after full sun exposure