[grc] the new yorker: the iPod of prison

[Brian Shiratsuki]

...The SRF-39FP is the gold standard among prison radios in part
because it runs on a single AA battery, and offers forty hours of
listening time—longer than an iPod Classic. Digital models can require
twice as many batteries, like the Sony SRF-M35FP, which runs on two
AAAs...

...There is also a bit of prison culture itself at work in the story
of the SRF-39FP. Radios like the one that was loaned to Demmitt are
usually left behind by inmates who have reëntered the free world. Some
prisoners believe that it is bad luck for radios to leave prison with
their owners, while others believe that taking them simply violates
the “convict code...”

from about eight years ago:
<https://www.newyorker.com/tech/annals-of-technology/the-ipod-of-prison>

``FP'' is for federal prison. the civilian version has an opaque case.