Watch the Aneros’s handle throb as he cums : that’s because his prostate is contracting as he shoots. Watch also the Aneros’s hinging point, just behind his scrotum : that’s also where his prostate is. In effect, as he cums, this guy is getting his prostate massaged by the Aneros in two ways : externally, via the hinging point, and internally, via the Aneros’s finger (that we obviously cannot see here). This dual action acts like an amplifier, making him acutely aware of his orgasm.
Interestingly, the Aneros is a passive device. It gets to be moved around by the contractions of the pubococcygeus (PC) muscles surrounding the anus. Since these muscles contract in response to the guy’s orgasm, the massaging action of the Aneros is necessarily in sync with the guy’s orgasm.
The guy who’s invented the Aneros definitely deserves a Nobel prize, as this is pure genius. Firstly, because it is a brilliant use of physiological knowledge. Secondly, because the resulting device’s action on a guy’s orgasm is just about life-changing (okay, that may be a tad too much, but you get the idea).