There is a ventilation system hidden in the base that ensures better milk flow while avoiding a buildup of air passing up through the bottle and into the nipple. (babieslounge.com)
Have someone massage you between the shoulder blades to help aid in relaxation resulting in better milk flow. (justbreastfeeding.com)
It features adjustable speed and suction to find your best settings for better milk flow, and three flange sizes are included for the best fit. (babycenter.com)