[QUOTE=summicron1;1367484]it would help if you'd tell us what it is or does./QUOTE]
It's a cheap, manual pump.
When you squeeze the rubber bulb, air pressure pushs liquid up and out the glass tube with the dropper end. Squeeze hard and a lot of liquid shoots out, sqeeze real gentle and you can add it drop-wise. When you release the pressure on the rubber bulb, air comes back into the test tube via the dropper end to replace the volume of liquid that was squeezed out.