While there is no universally agreed-upon definition, modern solitary—also called supermax, isolated segregation, and “the box”—is commonly understood to involve confinement to a small cell for 22 to 24 hours a day. Prisoners are not allowed to participate in leisure activities, have hobbies, or speak to others. They are often handcuffed and shackled when they leave their cells—if they ever leave. Perez says he eventually stopped even wanting to.