An aspirator is a device that makes vacuum, because of the Venturi effect. In the aspirator, fluid flows through it. The tube gets more thin, making the fluid flow faster, and making the pressure smaller. Then, vacuum is taken from it. The aspirator is also known as an ejector or a filter pump.
The most common type of aspirator is the water aspirator. It is used in laboratories for chemistry and biology. The aspirator has a fitted tee, which is attached to a faucet. It has a hose barb on one side. The flow of water passes through the straight part of the tee, which restricts the water flow at the intersection with the hose barb. The vacuum hose should be connected to this barb.