One of my students pointed me to the Femdefence site, based in Sweden. According to the site,
The project Femdefence is an attempt to contribute to the debate on men’s sexual violence against women in society, using the esthetics of design, and the semiotics of marketing.
Here is a schematic of their hypothetical "rape prevention device," found here:

Here is a video made as a part of this project. The second half is probably not safe for work.
It's sort of along the lines of the whole pseudo-Freudian "vagina dentata" idea. The video really freaks me out.
Just to clarify, this isn't an actual product, it's an art/commentary project. I assume this is too.
Thanks, Velanie W.!