his two-piece set includes stretch-fit cock rings in two sizes, rendered in soft, body-safe silicone for a snug but comfortable fit. The large ring has a 2-inch diameter ideal for standard use at the base of the penis (behind the balls), while the 1.4-inch diameter of the small ring makes it suitable for wear further down the shaft or at the base for a more intense and long-lasting erection. From Doc Johnson.