Exactly what you need for fuller breasts. Each cylinder is made of industrial strength crystal clear acrylic and will fit comfortably over your breasts. With this system you can enhance your breasts to a nice full size quickly. Just fit the cylinders over each breast and start pumping. Use the gauge to reach your full potential. Kit contains premium handle pump with gauge, split connector hose, and 2 air lock breast cylinders. Cylinders are 4.5 in. inner diameter and 4.25 in. deep.