Medela Valve & Membrane Set - 2pack
Medela Spare Parts - Valves and Membranes
These are sold in a packet which has 2 x Yellow Valve, and 6 x White Membranes.
Often the membrane needs to be replaced on a breast pump as they get wear and tear when you use the breast pump. And these tiny little pieces control the entire pump performance and section - they are so vital.
You may notice that the suction on your breast pump has decreased, so try replacing the membrane. This little disc controls the effectiveness of the whole breast pump, and is often the simplest and easiest solution.