An attachment module, having a fixing mechanism, couples detachably with a mobile device, thereby enabling a user to carry the module attached or detached from the mobile device. In at least one embodiment, the fixing mechanism includes an adhesive portion that binds the module to the mobile device. In at least one embodiment, the module holds a pair of wireless earphone to the mobile device in a position where the earphone speaker portion is generally positioned in line with the depth of the mobile device, thereby only minimally adding to the depth of the combined unit. In at least one embodiment, the module may be equipped with wired or wireless charging to charge its battery or that of the mobile device.