A woman can insert it like a conventional female condom, and it will protect her against sexually transmitted infections and unplanned pregnancies. And also against rapists - or so its South African inventor claims. Inside the anti-rape condom are tiny hooks which attach to the skin on penetration, trapping the penis inside. But is this a realistic response to South Africa's culture of violence against women?
Every 26 seconds a woman is raped in South Africa, says Dr Sonnet Ehlers, inventor of the anti-rape condom. The Rape-aXe, as it's called, is inserted with an applicator like a tampon. It then remains in place inside the vagina without the woman being aware of it. Like a conventional female condom, it will stop semen from entering the body, thus acting as a contraceptive and protecting the woman against HIV or other sexually transmitted infections. But there the similarity stops. The Rape-aXe is designed as a weapon against rapists.
After penetration, as soon as an attacker withdraws the first time, tiny hooks pierce the skin of the penis. The hooks don't go through to the spongy tissue beneath the skin, so there's no bleeding. Even if any blood is lost, it's contained within the condom, so there's no increased risk of HIV infection. Once the condom is on the penis, according to Dr Ehlers, it's then impossible for the rapist to remove it himself - it's simply too painful and causes too much skin damage. He will be forced to see a medical professional to have it removed - resulting in his inevitable arrest.
Dr Ehlers isn't worried that would-be rapists will think to check their victims for anti-rape condoms:
"I went into prisons, and I spoke to the rapists themselves. Most of them said to me that it would be such a surprise factor... I said 'and will you look for Rape-aXe beforehand?' And they said no because it's a hit and run, you've got to be quick and get away from the scene."
It might seem a high-risk strategy to use a device in self-defence which is liable to horrify and enrage a violent attacker, but Dr Ehlers doesn't believe her invention could put women in even greater danger.
"The men are violent already, so I cannot make them more violent with Rape-aXe. And another thing is if they kill their victim, he will be in double trouble. Because he's tagged, he cannot remove it, he's got to go to a hospital, and then he's identified. So now at least he'll be up for rape, and not for murder and rape."
This assumes, of course, that a rapist, finding his penis gripped by invisible needles, will pause to consider the legal ramifications of taking out his anger on his victim. Dr Ehler's website claims that at this point the anti-rape condom "will buy you time to get away". She puts it all down to the benefit of the "surprise factor".
"The moment he looks down - 'what happened to me?' - that gives you time to jump up and run. He cannot run after you. You must remember that it's attached to the penis during erection, and the penis wants to go back to normal, and it can't because it's almost like a splint that's on it now. He cannot urinate, because if he pulls the tip to cut that off so that he can urinate, he pulls the hooks deeper into his body."
Comments from South African men on the Radio Netherlands Worldwide website raise further concerns that the device is likely to provoke violence. Some responses to the news report on the condom were so misogynistic and offensive they had to be removed from the site. A further concern about the Rape-aXe condom is that it could potentially be used by aggrieved women to take revenge on men.
A 2009 study by South Africa's Medical Research Council revealed a chilling picture of male sexual violence in the country. More than a quarter of men questioned in the study confessed to having raped, some of them more than once. The report concludes that "Rape prevention must focus centrally on changing social norms around masculinity and sexual entitlement, and addressing the structural underpinnings of rape."
Dr Ehler's answer is Rape-aXe. And she's currently seeking donations to make 30,000 free anti-rape condoms available to the women of South Africa.