Here is the diagram review of iPhone 4 middle chassis assembly parts, from which you will see the full parts included into the middle plate. Meanwhile you will get to know where exactly each small part is located.
At the top ot the middle chassis, it includes iPhone 4 headphone jack flex cable, the iPhone 4 camera, the side buttons- power/volume/mute buttons. At the bottom you will see they are iPhone 4 dock connector flex which also is named charing port flex cable, the speaker, anntenna and home button with flex cable.
Please kindly take note proffessional skill is required for the iPhone 4 assembly or disassembly, so please make it absolutely sure before your DIY. Considering those iPhone end users who are unafamiliar with iPhone repair, Aviso supplies the full mid chassis assembly set for your easy replacement. What you should do is to upplug the back cover, front screen assmembly, mainboard and battery and then re-installed on the new mid chassis assembly. That's it.