Air displacement type for one-hand dispensing of fixed volume in routine laboratory procedures. Use disposable tips of non-wetting polypropylene. Precision of 100 µL pipet, ±0.5%. Thumb button operates spring-loaded stainless steel plunger, which moves through elastomer “quad-ring” piston seals Removable plastic nozzle insert on delivery end provides smooth, even flow of pipetted liquids. Built-in tip ejector can be operated with one hand. Can be calibrated to adjust the delivery volume. Range of adjustment is approximately ±10% of nominal pipet volume for distilled water at standard temperature and pressure.