Finally. An easy and convenient way to compare hearts! Hearts included: Fish, Amphibian, Reptile, bird, and mammal. It allows you to see in detail the structures of the heart and similarities and differences between different animal types. These specimens are set in transparent lucite resin. It's truly a unique and interesting way to study the inner workings of arguably the most important muscle of any living creature. Plus, they make a great Valentine's Day gift... 6.5"W x 3"H x 1"D