On the front there is the card reader in the far left and right next to it the headphones/mic jacks. Nothing else.

HP Probook 4520s Front

Right side begins with the two USB ports, modem, and the Super Multi DVD-RW.

HP Probook 4520s Right



The rear is reserved for the battery slot only.

HP Probook 4520s Rear



Left the heat dispenser, a VGA porst, LAN, HDMI eSata and one more USB.

HP Probook 4520s Left