The present invention relates to a coupling assembly used to connect a rotatable motor shaft to a drive shaft in, for example, a fluid pump. A mixed color group is defined based on data representing two or more colors, representing inks, and color parameters for each of the colors. The two frame buffers are each one word in width. With external dc voltage fields, whose strength or penetration into the interior of the rod system varies along the axis of the system, the ions can be collected or propelled along the axis of the system. A first series of through longitudinal grooves extends on a part of the length of the cylindrical central portion and on the insertion portion and defines a first section deformable radially inwardly relative to a non-deformed resting configuration. In one implementation, a system includes a network interface and a content source coupled to the network interface.