Stainless Steel Waved Penis Plug. Many men love the feel of something inserted into the urethra, this plug gives immediate stimulation with added sensation due to the unique 3 waves of pleasure design that gradually widen the further you insert. A hollow hole through the centre allows for the passing of fluids, so the wearer is still able to cum or pee. External Diameter 9mm & 12.5mm at largest point. Total Length 105mm with an insertable length of 90mm.