One side of this pewter pendant shows a fish of the class Actinopterigii, and the other side shows the fish’s internal anatomy. Great for ichthyologists and fisherfolk alike! The Actinopterigii, or ray-finned fishes, comprise the majority of all fish, and indeed all vertebrate, species. A large and diverse group of animals that has played a critical role in both aquatic ecosystems and in human history. Comes with an adjustable-length 2mm leather necklace cord. Dimensions (not including loop): 4.5 cm long X 2.6 cm tall X 1.4 cm wide Weight: 18.0 Grams