Parts for Apple iMac G5 20" family
Below are listed the three ranges within the 20" iMac G5 family. Working backards, the iSight version is easy to identify because of the video camera visible above the screen. Of the two previous ranges without the camera, one has a small clear dome protruding from the grill along the bottom of the main body. This senses the light level in the room and identifies the iMac as the Ambient Light Sensor version. If the iMac does not have this sensor, it is the original version.
If you are unsure which range you have, enter your serial number in the "Identify My Mac" box to the left. Click the "?" help link if you don't know where to find your serial number.