GotocutDuckbill Valve Silicone Diaphragm Compatible with Mommed S21 Breast Pump, General Breastpump Replacement Parts Accessories (6 Pieces Set)

Wasn't sure if these would fit my pump, I have a off brand s9 and they fit perfect.

They are soft and flexible with no sharp edges, very good quality. I like that they are transparent because it makes it easy to see if there is any dirt or debris. Love that they are made of food grade silicone which means they are safe. Love these valves. But they are a little pricey.