The purpose of the rubber hose is to connect the glass bottle to the plastic bottle(while the glass bottle is in the plastic bottle)
The hose I used fit perfectly in the plastic bottle, but had the same diameter as the opening of the glass bottle.
The small plastic tube takes care of this problem, though. I made it by cutting the end off a small test tube.
Cut off a piece of the rubber hose.
To attach the hose put caulk inside the it and push the plastic tube in(it shouldn't be a tight fit, because that would crack the tube, but it definitely shouldn't be loose)
Then put caulk on the rim of the rubber hose around the plastic tube and push it onto the glass bottle. Wipe off the excess and let it dry.
Wrap electrical tape around it.