Professional bottle-top dispenser for quantitative droplet measurement. It accurately adds droplets to containers for volume analysis, titration, dilution and other routine chemical analysis operations. A convenient instrument for everyday laboratory tasks. Large capacity design with 0-25 ml range. Ensures a safe, smooth and accurate dispensing experience and fits most laboratory reagent bottles to meet diverse experimental needs. High quality and reliability. Double return valve design prevents waste and drips. Low operating force and smooth plunger movement. Discharge pipe protective cover reduces leakage when the dispenser is not in use. Wide application and safety. Suitable for hydrofluoric acid, strong acid, fuming acid, alkali, solvents and extremely dangerous liquids. Resistant to most acids, alkalis and organic solvents; helps avoid the smell of fuming acids and foul-smelling liquids.