Features: These glow in the dark stones can be applied in varied settings, both indoors and outdoors. They're ideal for sprucing up landscapes, walkways, paths, and backyards or to use as fish tank gravel or large aquarium rocks. With these glow in the dark pebbles, you hold the freedom to decorate in any shape or form imaginable. Enjoy making distinctive designs with family and friends and bring an added touch of creativity to special occasions such as Christmas, Halloween, and other festivals. Specifications: Material: polystyrene resin Color: dark blue Size: about 1.8 inches/ 4.5 cm in diameter Weight: 4700g/10.36lbs Package includes: 300 x Glow in the dark rocks Notes: Manual measurement, please allow slight errors on size. The color may exist a slight difference due to different screen displays.