honsetly, I've worked with silicones and prosthetics a lot, and honestly can tell you that that looks like no prosthetic I've ever seen. It's way too stretchy and flexible to be fake, as well as the fact that it changes color, the foreskin stretches and distorts naturally, and his head changes shape as he gets aroused from stroking.
I'm telling you that it is a perfectly natural cock encased in a layer of disgusting saline, silicone, burst blood vessels, or some combo thereof. If you take a look at fakes like insane cock brothas, you'll notice the common element in all fake cocks is that they have no skin sliding over a shaft. It's really hard to apply a lubricated skin over another molded volume and have it hold up to rough fucking. Materials we've got for casting don't really hold up under stresses like pretending to fuck. The fake cocks are all a big slab of rubber.