Our dispensers and benchtop dispenser consist of drive and dispenser unit and are supplied to you with the stator, which is easy to assemble. The preeflow® eco-PEN is a rotating, absolutely pressure-tight, positive displacement system with self-sealing rotor-stator arrangement. The controlled rotary motion of the rotor transfers the medium by displacement in the stator. The medium is unchanged by this process. And simply by switching to reverse-flow, preeflow® ensures a clean and controlled stop of material or medium. No drips, no mess!