What is a two-phase pumping mode?

All BelleMa pumps offer a two-phase pumping mode – stimulation and expression – with specially designed pumping rhythm that mimics a baby’s natural pulling, squeezing, and suckling motion. The first phase is a fast and shallow stimulation to your milk ejection reflex (MER). The second phase is a slow and deep expression as how a baby sucks after the breasts have ejected a good flow of breast milk.