Just a FYI: The plunger ends in 3ml syringes make a silicone O ring if you need one. Just pull it off and cut it in half with some scissors. I least I think it's silicone. I'm an RN and we often call stuff that's "latex free" silicone made. Don't really know if it's true.
But then again I'm thinking of cutting my tubes that are too long so a drip tip works pressing up against the ceramic cup in all of them. Wish they were all the same distance from the cup but they differ. You think it's safe for any other drip tip other than aluminum and ceramic to touch the ceramic cup? I'm thinking the other ones will melt.
the one they include will lol