A motor of industrial quality provides the power to drive the up-and-down stroking motion for any penis size. Unlike all other masturbators that are made in a one-size-fits-all design, the Autoblow 2+ is the only device that uses interchangeable sleeves in three different sizes to ensure that you experience great sensations, whether your penis is slim, average, or particularly thick. The circumference ranges from 10 to 14 cm.