This is the first and currently only unit of its kind for male offenders, where the whole environment is focused upon family, parenting, and relationships. (fatherhoodinstitute.org)
The photons are not only the units comprising the flow of information, but also the ones that control the device. (sciencedaily.com)
It is only a unit of exchange, like trading cigarettes in a prison camp. (alephblog.com)