I used to think it was silicone myself, but several people are now saying Eddie uses a combination of high pressure pumping and synthol to make his cock so large. If you look at his body especially his wings, as they call them, chest and abs you can see the signs of synthol use. It would make sense that if they worked well for his other muscles he would try to use them on his dick. Combine that with pumping and some sort of cockring I could see how sythol could stay in and around the tissues in the penis and possibly result in altered tissue mass. It would explain also why his penis has maintained it's shape despite the massive size. If it were silicone, flaccid, it would looked deformed and his head would not be visible at all. It's a shame he's such an ass because I am sure there are things we could learn from him in regards to penis enlargement.