An expandable socket for attachment to a portable media player or a portable media player case. The expandable socket generally includes a platform, a skin coupled to the platform, a button coupled to the skin opposite the platform, and a biasing element. The skin includes an outer wall, an inner wall spaced radially inward of the outer wall, and a cavity defined by the inner wall, wherein the skin is deformable between a collapsed configuration and an expanded configuration. The biasing element is arranged within the cavity of the skin between the platform and the button, such that the biasing element is at least partially surrounded by the inner wall of the skin. The biasing element is configured to bias the skin into the expanded configuration.