Does not “glow in the dark”: the glow effect will only occur under actinic lighting; blue or purple light is recommended. Ideal decoration: Incredibly detailed replica of sleek floating jellyfish (doesn’t move automatically like a real bouncy jellyfish.) FOR YOUR FISH: Made of eco-friendly, non-toxic, odorless and durable silicone. EASY TO USE: Simply install the suction cup and it’s secured with an invisible cord. The suction cup must be at the bottom of the tank and the rope and jellyfish must be below the waterline. A world of 6 colours: in 5 x 12 cm format. The package contains: 6 x artificial jellyfish in blue, purple, green, orange, pink and yellow