The woman inserts the latex condom like a tampon. Jagged rows of teeth-like hooks line its inside and attach on a man's penis during penetration, Ehlers said.



Once it lodges, only a doctor can remove it -- a procedure Ehlers hopes will be done with authorities on standby to make an arrest.



"It hurts, he cannot pee and walk when it's on," she said. "If he tries to remove it, it will clasp even tighter... however, it doesn't break the skin, and there's no danger of fluid exposure."



Ehlers said she sold her house and car to launch the project, and she planned to distribute 30,000 free devices under supervision during the World Cup period.



"I consulted engineers, gynecologists and psychologists to help in the design and make sure it was safe," she said.



After the trial period, they'll be available for about $2 a piece. She hopes the women will report back to her.



"The ideal situation would be for a woman to wear this when she's going out on some kind of blind date ... or to an area she's not comfortable with," she said.