A jumper sleeve configured to be installed on an outer side of a male F-connector to facilitate easy connection of and maintain ground continuity across the male F-connector and a female F-connector. The output of circumferentially distributed sensors is used to calculate the asymmetry of a flow field. A voice coil motor rotates the actuator arm about a pivot to actuate the head radially over the disk, and a secondary actuator adjusts a skew angle for the head while using the write element to write the servo sectors to the disk. The hub includes a first tab extending outwardly at a position which is exposed from the outer shield, and the outer shield includes a second tab.