Pumping shouldn’t hurt. When pumping is uncomfortable or hurts, it can suppress the amount of milk you are able to express. To avoid discomfort and help you maximize your milk expression, the right flange fit is essential. The Evenflo Feeding AdvancedFit™ Flange System includes multiple flange sizes, ranging from X-Small (21.0mm) to XX-Large (36.0mm). The X-Large (33.0mm) and XX-Large (36.0mm) AdvancedFit™ Flanges compatible with all Evenflo Feeding Advanced Breast Pumps, including the hospital strength Advanced Double Electric Breast Pump, Advanced Single Electric Breast Pump and Advanced Manual Breast Pump. The flanges are 100% free of BPA, polycarbonates, PVC and phthalates and are made of FDA-approved food grade material.