The vibrations of the vibrator can be felt inside the masturbator. The nubs on the inside provide heavenly stimulation, and the dense back completely envelops your penis. The attachment fits wall-mounted vibrators with an average diameter between 4.5 and 5.5 cm. For larger wall vibrators, simply remove the detachable cap and then slide the attachment onto the tip. Thanks to the transparent material, you can watch the action.