A golf club head having a hollow portion is partly or entirely provided with a PCCP structure excluding its face portion. A request is received to track a mobile device. In another preferred embodiment the body of dusting section has a mid-section that can be pivoted to allow the dusting elements to rotate about an axis set at an angle to the axis of the extension member. An EEPROM cell pair includes a first non-volatile memory transistor, a second non-volatile memory transistor and a source access transistor. The seat member may be removably installed in an operative position on the upper side of the first platform through a releasable engagement of the first and second male-female engagement members with one another.