The Nipple Amplifier nipple suckers are an erotic way to achieve fuller and more aroused nipples. This enlargement system includes four graduated O-rings that are placed over the nipples to properly stimulate them. Simply choose the desired ring size, place it over the open end of the pump, cover the nipple with the glass pump, and then squeeze until the desired nipple size is reached. Next, slide the stretchy rubber ring over the swollen nipple. Two differently sized pumps are included for a perfect fit for any size. Dimensions: Pumps are 6.5 cm long, the large pump opening has a 1.3 cm inner diameter, the small pump opening has a 1 cm inner diameter, and the O-rings vary from 1 to 1.4 cm in diameter. Material: Rubber, glass. Color: Black. Note: Includes two pumps and eight rings.