Momcozy S9 Pro / S12 Pro Double – Double Layer Sealed Flange Full Set

2.Step 2: Secure the Top Silicone Diaphragm:Press along the perimeter rim.Place the circular silicone diaphragm into the top seating ring of the collector cup. Run your thumb firmly around the entire outer rim to ensure it snaps down flush, preventing air from leaking into the motor base.