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Below the 15R 7520's keyboard is a large touchpad with two discrete mouse buttons. The touchpad is comfortable to use—it's just big enough, it's sensitive and responds to multitouch gestures smoothly, and its buttons are large and easy to press. If you want to use an external mouse, you can disable the touchpad by using the F3 key, and a small orange light above the touchpad indicates when it is disabled.
The 15R 7520 has plenty of ports, located on both sides of the laptop. On the right side you'll find two USB 3.0 ports, an ethernet port, and the optical drive; on the left side are two more USB 3.0 ports, VGA-out, HDMI-out, and microphone and headphone jacks.
On the front is a multiformat card reader, and on the back is a small metal switch. Flicking with battery such as Apple PowerBook G4 15 inch Battery , Apple A1012 Battery , Apple M8511 Battery , Apple M8244 Battery , Apple A1079 Battery , Apple A1078 Battery , Apple A1148 Battery , Apple M6091 Battery that switch pops the honeycomb-pattern cover plate out, allowing you to remove it and swap in another plate. This is kind of cool from the standpoint of someone who enjoys changing designs every so often. Lids cost an additional $30, and come in pink, blue, and red. Removing a plate is easy, but installing one is a little tricky, since you have to press pretty hard on the corners to get it squared away.