Glow in The Dark Stones pebbles Rock 100pcs x color or colorful Walkway Fish Tank Parterre Garden D?cor set28 size about Length:2-3CM width(1.5-2CM), weight : about 2-3g (1pc) Material: Photoluminescent pigment + resin, this powder is "charged" with any source of light (sunlight works great) and will glow for 2-24 hours afterwards, depending on the color and charge time. have 100 xColor:11 colors, as the picture shown.Have Blue&Green,Yellow&green,Sky Blue,Purple,Orange,light orange,yellow,Green,Blue,Pink,Multi-color Delivery time: By Airmail: Generally, delivery to USA takes about 10-35 days. Delivery to Canada,AU, UK, and other European countries takes about 14-28 days.