Basically this. You have an inflatable buttplug attached to a pressure sensor and a vibrator. When you're about to cum you clench your butt which is detected by the pressure sensor and the vibrator then stops. It waits a few seconds for you to calm down and then starts again.
This sounds magical.....how much was it? And does it work?
A lot and yes with a bit of calibration Checkout @maustec.io
I'd recommend calibrating on the over sensitive side. I find that as you go through more and more cycles, it gets closer and closer, the first time I used it, on my 68th cycle it cut out just as it took me over the brink for a full on ruined orgasm!