This invention includes an adjustable boat top, that can be lowered in order to permit the boat to travel under bridges and other obstructions that might otherwise preclude the passage or movement of the boat. A contact surface of the cleaning member with the cleaning target includes a plurality of regions of different toner-releasing ability. In the preferred embodiment of the invention, the mixture comprises a range of 90 to 97 percent by weight of powdered heavy metal, and 10 to 3 percent by weight of the powdered metal binder. The substrate insulating layer is then selectively etched to define a second array of nano-channels therein. The magnetic field projected by the assembly varies as a function of the orientation of the magnets.