Many will not know a teny unit: Tt's the kind of device, that's used for genital torture. (In porn, by profs and other "fetish people")
I know it and I can say it is really hot. It's (as far as I know) impossible to harm anybody's genitals with it, but you can cause pain, that's far to strong to bear, well, to strong for me at least.
The only thing to mention might be, not to put it on to loosely or to fasten the two contacts too near to each other.Then the pain will be like a hot needle, very strong and just on a tiny pice of skin. That way you will maybe even be able to aktually harm the skin there.
The tighter you fasten it (with two blank wires if you want to be cruel.) the more it will feel like your whole shaft, way into the body, is on fire and beeing burt away. ... !
If you put it up high, I have to mention.
If you don't, you can also make very light to vibrating pain that might even cause an ejaculation. So be careful girls: Don't be too shy. ;-)
I have one or another video I like, and maybe will be (re)post one of them here.
I masturbate with my unit from time to time but...
You can not torture yourself over a certain point of course.
I would so love to be tied and my cock be tortured by some stranger woman. Far OVER the point where I would stop it myself....
In some viedos you see them putting down a metal rod down into the guy's urethra and connecting it to the power. That is something that looks nice but brings the two contacts too near together again and so it doesn't feel the way it looks and I would not want to have this done to me. But of course..., who am I to say what I want, once that SHE is in control...!