KNAUER pump heads are equipped with blind fittings. These are screwes closed at one edge that prevent the wetted parts of the pump to dry during delivery. Please unscrew these and be aware that the pump head will be filled up with alcohols so wear proper gloves before doing that. Further details on how to connect correctly the pump to the flow depend on the type of pump you purchased (HPG, LPG, isocratic etc.). Please consider the proper section in the user manual you received together with the pump. You can also find all user manuals here.