Figure 1. This 85-cm-high cage meets the European minimum requirements for primates of the body weight class 6-7 kg. It allows the installation of a perch, or other climbing surface, in such a way that an animal can normally sit and walk not only on but also under it. The U.S. minimum requirements of 76-cm height do not fulfill this condition.
Reinhardt, Viktor; Liss, Cathy; Stevens, Christine. "Comparing Cage Space Requirements for Nonhuman Primates in the United States and in Europe," Animal Welfare Information Center Newsletter, 7(1):12-13, Spring 1996.