This old Sony Walkman is prison's most popular gadget

IT DOESN'T have a touchscreen, it can't connect to the internet, it doesn't have any fancy features and doesn't even sport a sleek, modern design. But an old, Sony Walkman is the most popular gadget going for prisoners in America.

In an article for the New Yorkerit's revealed that the Sony Walkman SRF-39FP is called 'the iPod of prison'. The pocket AM/FM analog radio made specifically for the prison market for the past 15 years is an essential item for a stint in the cells as it packs all the specs desired for life on the inside.

The bulky device is made from a see-through plastic body so no contraband can be hidden within, it provides 40-hours of listening run on just one AA battery, a super strong antenna ensures inmates can pick up stations through the thick concrete walls and it's near-indestructible thanks to the sturdy casing.

It's also cheap at under US$30, but most inmates won't have to worry about cost as many prisoners hand over their used devices when they are released on the count that many believe it's bad luck to take your Walkman on the outside, and also because it breaks prison etiquette to leave with them.

However, those who do take them out can expect to fetch a pretty cent or two for their models as collectors of rare radios are willing to pay above and beyond to own one.

The Walkman not only delivers some 'jail house rock', but can provide inmates with a link to what's happening on the outside world and also gives a moment of personal privacy in a practise prisoners refer to as 'headphone myself'.

For prisoners wanting to go a bit more high-tech there is an updated version of Sony's prison Walkman complete with digital display, but it requires two AAA batteries, is not as rugged, costs more and will need tracks to be downloaded onto it. In this rare instance it seems better off not upgrading.