Designed for use with Medela's Flex & Pump in Style with MaxFlow, Swing Maxi, Solo, and Freestyle Flex breast pumps (sold separately) Closed system with Overflow Protection safeguards your pump by preventing milk from flowing into the tubing or motor Connectors allow you to pump while reclining for a more comfortable experience Connectors are easy to assemble and clean for a hassle-free experience Works with all PersonalFit Breast Shields and sizes, including the PersonalFit Flex Breast Shields BPA-free construction provides safety and additional peace of mind for you and your baby Authentic spare part is ideal for replacing a lost or damaged part or for keeping a spare set of connectors on hand for travel or work