Supreme duet is the most advanced, next generation, highly robust and reliable bottle top dispenser designed through years of research. Supreme duet has a recirculation valve for redirecting the liquid into the bottle and rinsing the instrument without dismounting from the bottle. Supreme duet with a worldwide patent can be used in 4 modes: dilution, rinsing, dual liquid handling and re-circulation all in a single unit. Supreme duet has a smooth and soft plunger for easy working in difficult laboratory conditions.