Quickly adjust volume by turning the thumb knob until the yellow sight line corresponds to the desired setting on the volume window. Tighten a brass set screw, and your volume setting is locked in place.
Polypropylene construction and durable design reduce friction wear and increase precision. A piston of PTFE ensures complete sealing in a polypropylene cylinder. O-rings are not exposed to friction wear. You can draw and deliver precise samples for the entire life of the piston and cylinder. Lock volume in place with set screw.