The Supkeyer 5Pcs Artificial Glowing Effect Fish Tank Decoration Aquarium Jellyfish Ornament is a great way to add some style and elegance to your aquarium. These fish tank decorations are made of soft silicone and fluorescent powder, and they come in a variety of colors including pink, blue, yellow, green, purple, orange, and more. They also have a diameter of approximately 5 cm/2 inches and a full length of approximately 14 cm/5.5 inches.