Haasman: I confirm what csnow has already noted. The 1/2 inch OD, transparent, braided PVC tubing is inserted into the top flare of the dipstick tube. That O.D. will not allow the tube to enter beyond the flare and makes a tight seal. The transparent tube is apparently heat resistant enough and the internal braiding makes it strong enough to withstand temperature and vacuum. Its neat to watch the last few bubbles of oil pass along the tubing, signaling that the sump is dry.