With a 0.66-inch screen, the Fly is apparently the world's smallest mobile phone. It's not the only nanophone in existence, but they're all made by companies you've never heard of, and you won't find them in major electrical retailers. You might, however, find them stuffed among chargers for Nokia 3210s at your local phone unlocking booth, and they're all over Amazon and eBay. They cost about $40.

In the early-2000s, mobile manufacturers tried to make handsets as small as possible. In the 2010s, smartphones were sold on how big their screens were. In 2016, the tide might now be turning once again: Apple's newest phone model, the iPhone SE, boasts a relatively minuscule 4-inch screen. But Apple have some distance to go before they can match the Zanco Fly.

If you think this sounds like wild extrapolation—after all, lipsticks are around the same size, and you don't get articles about whacking those up your nether regions—have a look at how some of these phones are sold. Many, for instance, claim to be 100 percent plastic, or come with a " beat the BOSS " tagline, which is to say they claim to be undetectable by body orifice scanners.

Similar phones were in the news back in 2013 when handsets shaped like BMW key fobs—also largely plastic, and in a convenient pellet shape—appeared. Those keyfob phones are apparently illegal now—if only due to trademark infringement of that BMW logo—but phones in prisons remain a big problem. In January it was reported that seizures of mobile phones had hit a new high in England and Wales: almost 10,000 phones or SIMs had been confiscated in one 12-month period, significantly outnumbering drugs confiscations.

Amazon customer reviews for various brown-phones range from the subtle to the straightforward. One reviewer reports that the phone is "very small and easy/painless to hide," but is concerned that this model isn't 100 percent plastic, so won't necessarily beat the BOSS. They give the phone just one star, "as I imagine that most people will want a phone like this for a certain purpose."

Phones up butts are frequently reported in the news. Last summer, for instance, a guy beginning a 16-month stretch for fraud was found with a phone, plus charger, up his ass. This February, a triple killer in a New South Wales maximum security prison went on hunger strike for 12 days in an attempt not to eject a phone detected by a BOSS unit ( the phone eventually emerged on February 25). A year before that, the butthole of a guy being admitted to HMP Manchester was found to contain four mobiles, four sim cards, and four chargers . Then there's André Silva, whose anus was the portal to an Aladdin's Cave of contraband: according to one report , Silva's back passage contained "two mobile phones, two batteries, pliers, two drills, eight pieces of a hacksaw, five nails, and three SIM cards."

Carl adds that cavity searches do occur on your way into prison, so bumphones might not be practical when you're on your way in, but there are plenty of other ways to get things into prisons. Having stuff chucked over a wall is one spectacularly basic method; going fishing is another—last year someone was given two-and-a-half years for tying drugs, a knife, and a McMuffin to fishing line that a prisoner was hanging out of a window. But regardless of how they get in, once phones are inside the prison, they need to stay hidden.

"Phones are everywhere," says former inmate Carl Cattermole, whose prison survival guide at prisonism.co.uk provides a fascinating insight into life behind bars. "Staff bring them in, or you could buy one from another inmate by doing them a favor or giving them something, or you phone up someone outside and they pay cash to someone else. People normally use them in their cell with people looking out, but it gets to the point where people are just using them in the changing rooms for the gym like it's the outside world."

Those, of course, are just the phones that have been found, and perhaps that's where these $40 buttphones come in; they're not only hard to detect, they're quick and easy to get hidden, too. Obviously it's possible to get reasonably large items up your bottom, otherwise fisting wouldn't be such a popular hobby, but for the purposes of easy storage and retrieval, you're going to want to go as small as possible. "Things like iPhones are rare in prison," Cattermole says. "Most phones go up a bum at some point or another, so fuck an iPhone 6 Plus, or, rather, don't. You'd look like Spongebob Squarepants: a rectangle with limbs hanging off. Having said that, I knew a dwarf who plugged a Blackberry."

And yes, on one hand it's all very amusing that some fella's doing his best not to shit out the latest Samsung. Equally, if someone told you that you couldn't speak to your loved ones whenever you wanted, you'd probably do the same. Christ—considering the blind panic most of us experience when our battery drops below 30 percent, we'd probably be eyeing up the lube if we were facing a single day without Facebook. "I think this is something you don't understand unless you've been to jail," says Carl. "It's the emotional segregation. I'd find a way to put a phonebox up my bum if it meant staying in contact with my loved ones."