When the vas deferens is cut, it’s no longer connected to the seminal vesicle, which produces the ejaculatory fluid and also serves as the place where this fluid and sperm are mixed to produce semen. When the device—which, again, functions like a light switch or castle gate—is implanted, the severed ends of the vas deferens are fitted into the valve, then held in place by a connector, similar to the way a garden hose might fit into a spout. Switching the device on prevents the introduction of sperm into ejaculatory fluid, effectively sterilizing the user. Switching it off lets the sperm flow back into the fluid, once again producing semen.
As a vegetarian, Bimek ruled out animal testing from the get-go, opting instead to go straight to the human body—or, in this case, his own scrotum. This step in and of itself proved difficult because he had to find someone to approve the surgery, which he eventually did through his local hospital’s ethics committee.