... ), to generate negative pressure, suck in quantitative (adjustable) liquid. It has theadvantages for convenient use, reliable performance.Main Specifications:5 ... 1-2 seconds, after that, take it out from the liquid, and do not let it touchanything.4. Move the suction nozzle to ... button, exhaust all the liquid, the suctionnozzle should be slided out along the vessel wall, then slowly release the button, ...