Volumetric pipette
This kind of pipette has a large bulb on the top end, with a long narrow tube on the other end. It is used to accurately measure small amounts of liquids. You use it by placing the long, narrow end in the desired liquid, then squeeze the top end, the part with the bulb. Pipettes function on suction, sort of like sucking the air out of a water bottle. It gets harder and harder to suck the air out of the water bottle as the inside gets closer to a perfect vacuum. When the apparatus is removed, a small "sucking" sound may be audible. This is the air again reaching equilibrium with the outside air, as outside air rushes in. The same thing goes for a pipette. When you press down on the flexible bulb-like part of the pipette, you create an absence of air in the pipette. When you remove the pressure, the long part of the pipette sucks in the liquid that the end of the pipette is immersed in. A volumetric pipette uses measurements to suck up the exact amount needed of the liquid it is immersed in.