Stronic Zwei is a pulsator, not a vibrator. Stronic Zwei delivers thrusting motions (back and forth movements) as opposed to the buzz generated by vibrators. Stronic Zwei is unisex (fit for anal or vaginal play.) Stronic Zwei can be used Hands Free in a variety of positions because it's back and forth thrust motions keep it in place inside the user! Stronic Zwei allows user to surrender control in a whole new way.