The stop-bar on the Fusion 6000 high-pressure syringe pump is designed to allow you to control the distance the pressure block stops at. It is easily adjustable, simply twist the knob and position the stob-bar to the desired place and tighten the knot.
CAUTION if you are using a glass syringe be especially careful in making sure that the stop-bar is adjusted in the proper position to prevent your syringe from breaking.
Below is a demo video:
To learn more about the Fusion 6000 high-pressure syringe pump visit the product details page here.