It is a glass tube at one end of a long taper. The other end of the bulb and the worn tires. Use the dropper to suck reagent bottle to drip into a test tube filled with other substances.
Glass tube with one end long taper And at the end of the other side with rubber bulb wear. The eyedropper is used for absorbing reagent from a bottle to drip into other substances that test tube packaging.
There is a glass tube on the end of the slender long and at the other end is a protuberance is wearing rubber drip tubes used for vacuum cleaning agents from the bottle to drop down in the test tube is another matter.