The characteristics of a long glass tube, one end 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.
At the end of a glass tube with a long taper side. 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 at the end of the slender small and at the other end is a protuberance is wearing rubber drip tubes used for vacuum cleaning agent from the bottle to drop down in the test tube is another matter.