Help with Innosense Breast Pump spare part

[abikirk]

I've been using an Innosense Breast Pump (from Mothercare). It came with two of the little blue valves that attach to the part between the pump and the bottle. Unfortunately one of them disappeared down the sink. I still have the second to use, but want to try and order a replacement in case I lose that too. I've contacted Mothercare Customer Service, and they say only two spare parts are available: the overflow valve and the silicone membrane. Helpfully they won't tell me what these actually are! Can anyone tell me whether the part I need is called the overflow valve? I can't find out anywhere.
Thanks, Abi.

That's a bit rubbish of them. Hopefully this will bump for you.

I have the same pump and I would say the bit you need is the silicon membrane. I assume it's the green bit on the cone like bit. The overflow valve sounds like the white bit that goes in the top.