Quick Disconnect Internal O-ring
 

There is a small square ring that I lost when I was taking apart the Q/D to clean it. This square ring seals between the clear plastic poppet and the black portion of the Q/D. Does anyone know the sizes for this square-ring? I'd like to replace just the ring rather than the whole Q/D.

thanks,
Adam

The part number is listed somewhere in HBT forums, I bought a but load of them from McMaster, If you can't find it here, pm me and I look when I get home.

I did try looking briefly and hadn't seen it. I will continue to search!

McMaster-Carr, 4061T118 pretty sure this is it. I searched my invoices online, this is the only square one I bought, so its gotta be it.

here are some others I bought for the diptube and lid, posts.