Pigeon Breast Care Pump Plasticwhen preparing to breastfeed, it is recommended that you express any milk remaining in your breast from the previous feeding. For mothers with flat or depressed nipples, the Bigen Breast Pump can also help to safely and gently retract nipples. The plastic shield fits the natural extracts remaining breast milk, improving the lactation of breast milk, preventing blockage of ducts and stimulating the mammary gland.