The "deep throat" cup of the tenga masturbation cup series lets you experience a deep sucking sensation… special valves create a virtual vacuum inside the cup; to deliver an amazing sucking sensation. the top air vent can be left open or closed; with fingertip; depending on your suction perferences. the unique pinched-in shape of the cup helps to achieve an unparalleled tightness. these advanced features combine with an arousing "slurping" sound and vibration give you the feeling that you're enjoying a real deep throat experience. the "hard cup" provides a deep and intense suction combined with a hard tightening action