Nipple Bulb comes complete with 4 nipple erection rings. 2″/5cm suction bulb for gentle, pleasing pleasure. Clear tapered vacuum tube for comfort. The Nipple Bulb is a gentle little suction device for enhancing and raising your nipples. Just apply to the nipple and squeeze for light, comfortable suction. To use the nipple rings, slip the ring on to the vacuum tube before suction begins, then slide off the tube onto erect nipple.