What is SuperMax?

"What is a SuperMax prison exactly? According to the Spunk Library SuperMax prisons are essentially solitary confinement for the duration of the sentence. Prisoners are locked into a small cell for 23 hours a day, (1 hour a day “exercise” in a different concrete room with a pullup bar) communication is restriction or totally denied, etc, etc. This quote from the article is notable:

The effects of solitary confinement have been known for more than a century. The following is a quotation from an opinion by the U.S. Supreme Court in 1890: “[E]xperience demonstrated that there were serious objections to [solitary confinement]. A considerable number of the prisoners fell, after even a short confinement, into a semi-fatuous condition, from which it was next to impossible to arouse them, and others became violently insane; others still, committed suicide; while those who stood the ordeal better were not generally reformed, and in most cases did not recover sufficient mental activity to be of any subsequent service. . . .” "