Replacement Valve and Membrane for Medela Breastpumps (Swing, Lactina, Pump in Style), 4x Valves/6x Membranes, Part #87089
BPA Free. Test reports are available online. Membrane are more flexible than the OEM membranes to respond faster to the pressure change during pumping. Valves are better angled for less trapped precious breast milk in them. Storage case included provides better protection plus it is more convenient when traveling. Convenient and valued pack of 4 valves and 6 membranes