How do Manual Breast Pumps work?
Manual breast pumps use a system of two cylinders to create suction. Once the breast-shield is placed over the nipple, a small cylinder-shaped tube is pumped in and out of a larger cylinder to create a vacuum that expresses milk and collects it in an attached container. Manual pumps have a handle or lever that is squeezed to create suction and express milk from the breast. Another type of manual pump is a bicycle horn pump which consists of a hollow rubber ball attached to a breast-shield.
