Penis slings are basically cock rings with an added feature: They tickle the taint. That's right, that little area between the penis and the anus, which you may not know is an extremely erogenous zone, is an incredible source of pleasure. They use a tongue that extends back over the perineum and bats and massages it as you go. The net result is that it not only increases your pleasure during sex, but it also greatly emphasizes the size of your package. The most popular models are made of silicone, which makes them much easier to put on and take off. If you don't have one already, they are definitely worth looking into!