Medela's PersonalFit Connectors are engineered, tested, and approved to work specifically with your Medela breast pump and seamlessly attach to all PersonalFit breast shield sizes. Understanding your breast shield size and ensuring a proper fit is essential for both comfort and optimal milk expression, these PersonalFit Connectors were designed for seamless integration with your PersonalFit Breast Shields and breast pump. Compatible with Pump in Style Advanced and Symphony breastpumps. Note these breast shield connectors are NOT compatible for use with Pump In Style with MaxFlow, Freestyle Flex, Freestyle, Swing, and Harmony breast pumps. Medela pump parts and all other Medela products that come in contact with breast milk are made without BPA, for the added peace of mind that moms deserve.