iPhone 4 and 4S Power and Lock Button
Replace the external power/lock button cover. This part does not include the internal power button switch and is compatible with all iPhone 4 and 4S models (GSM and CDMA)...
iPhone 4 Home Button Assembly
This part includes the external home button cover as well as the internal home button switch and cable. Compatible with all iPhone 4 models: GSM (AT&T) and CDMA (Verizon)...
iPhone 4 and 4S Volume Button
Replace the external volume button covers. This part does not include the internal volume button switches.
In June 2010, Apple diverted from previous designs with the iPhone 4. Featuring glass front and back, a front and rear camera, and 512 MB RAM, the iPhone 4 met a highly favorable reception. The iPhone 4 is the first iPhone with video conferencing capabilities over Wi-Fi. It runs the A4 Processor just like the iPad. It has 5MP camera with LED flash and shoots full 1:1 720p video at 30 FPS.