The illustration depicts a lateral fluid percussion model being used on a marmoset, a species of New World monkey belonging to the genus Callithrix. This setup is commonly used in traumatic brain injury (TBI) research to simulate conditions and study the impacts on primates. A marmoset is positioned with an apparatus attached to its head where fluid percussion is applied to mimic brain injury scenarios. The scientific apparatus is shown alongside the animal on a laboratory bench, indicating a controlled experimental setting. The equipment consists of a fluid delivery system and measurement tools for precise application of pressure, crucial for studying the physiological and neurological responses. The model is used in neurology and primatology research to better understand brain injury mechanisms and potential treatments.