A magnetic head having improved overwrite capabilities and reduced fringing fields are described along with methods of making the same. The mesh is most preferably a soft and lightweight plastic which is not harmful when swung by the animal. An optimal node is selected based at least in part on the system weight, quality of service requirements, among other factors associated with each available node. The movable member can be coupled to a gear to permit movement of the movable member following implantation of the port within a subcutaneous pocket. The memory can be characterized for cell stability, write margin, and read current margin in this manner; the method can also be adapted into a manufacturing margin screen, or used in failure analysis. When the output current is less than the first predetermined limit value, a step is conducted where the output current is regulated by modulating the pulse width of the signal sent by a driver to the control node of the power device.