Yes, all our electric pumps are a closed, hygienic system. By using a specially-designed diaphragm and diaphragm cap, the pump is guaranteed to prevent milk from backing up into the tubing and into the motor unit. This is important from a hygienic perspective (condensation and/or milk in tubing can cause mould and bacteria growth and build-up) and from a perspective of understanding how important every drop of your milk is to you and your breastfed baby.