I had to drill 2 holes in the canning jar lid using a dremel. I used two correct sized rubber grommets (to seal the hose holes) These are a God send, as I don't have to worry about the seal. The screw ring is the only thing to twist, so you don't get all twisted in a knot with the tubes and all. I can put as much or as little MMS in the pint sized wide mouth canning jar, which is meant to seal, and pump away!!! It's so handy, I'm thinking about making them available for others.
The baby bottles I have a hard time with, as they were made to not seal, (so the nipple doesn't collapse when the baby sucks on it.) Twisting the whole thing is a pain! Glass baby bottles are hard to wash and even harder to come by.
By the way, The tubing is Polyethylene.