Yes, the OFM pump (MPP102PC) has push and pull options in the same unit. Either one pump head can be used for push and the second pump head for pull or, with special tubing (e.g. OFM-PP1-LT-1000), push and pull modes can be performed using only one pump head. Calibration is necessary as different tubing materials and diameters are available. The calibration factors are pre-determined to save you time and money and improve your research quality. Thus, calibration can be performed when you enter the calibration factors stated on the label of the packaging. You can find the details in the MPP10xPC user manual.