Abstract: A screw-free metallic jacket for a mobile phone which is provided with multiple through holes corresponding to function keys of the mobile phone and a slot hole corresponding to a slot in the mobile phone. The metallic jacket contains a fixing projection at a side of the metallic jacket opposite to the slot hole and at an inside of the metallic jacket for withstanding an edge of the mobile phone. A retaining nut has a soft front edge capable for closely fitting with the slot such that the retaining nut can be ensured to be firmly inserted into the slot in the mobile phone. The retaining nut has a flange at upper and bottom sides of the retaining nut, wherein the flange abuts against an inner edge of the slot hole in the metallic jacket such that the metallic jacket can be fixed with the mobile phone without any screw.

Abstract: A novel headset is provided herein which has a built-in power supply and combines the audio connection of the headset and the electrical connection of the power supply inside a single physical cable to an appliance. On the male plug of the cable for plugging the appliance's female jack, there are four ring connectors for the connection of the left audio channel, right audio channel, power supply, and a common ground for both the audio channels and the power supply, respectively.