A power receiving port includes an inlet, a pullout hole for a pullout type cord, and a selector switch. The method includes initiating a session and selecting a session type by the user. The left and right ocular parts each have at least two reflecting surfaces 12R and 13R. The reduced detachment of crystal grains makes the magnetic readwrite head more resilient to chipping, which allows the magnetic readwrite head to have a lower and more stable flying height that increases recording density.