Keep your nipples stiff and sensitive with this nipple sucker and experience the pumping pleasure! Squeeze the small balloon until the desired result is achieved. Repeat these steps with the other nipple. In order to get the nipples to swell even more, repeat the steps once again. Enjoy! Specifications materials Plastic, PVC. Sucks and pumps. Keep your nipples stiff and sensitive with this nipple pump. Unisex. The easiest way to stimulate nipples.