System Overview 1-7Back FeaturesThe system's secondary lithium-ion (Li-Ion) battery or an optional Extra Life Li-Ion battery canbe installed in the battery bay at the back of the notebook.Left Side FeaturesThe left side features are shown in the following figure. Feature descriptions follow the figure.Left-side featuresA ñ AC Power Port D ñ RJ-11 JackB ñ Vent E ñ USB PortC ñ External Monitor (Video) Port F ñ LAN Cable Jack! AC Power Port ó Attaches the notebook to a power source, such as the AC adapter.! Vent ó Allows the system to cool properly and maintain a safe operating temperature.! External Monitor (Video) Port ó Use this port to attach an external monitor to thenotebook. The LCD display and external monitor can be run simultaneously or run alone.! RJ-11 Jack ó Connects the internal modem to an analog telephone line.! USB Port ó The Universal Serial Bus (USB) port allows connection of up to 127 USB-equipped peripheral devices (printers, monitors, scanners, etc.).! LAN Cable Jack (optional) ó If the system has this feature, the system ships with a localarea network (LAN) adapter cable to connect the jack to a LAN.Right Side FeaturesThe right side features are shown in the following figure. Feature descriptions follow the figure.Right-side featuresA ñ Headphone Jack/External Speakers D ñ PC Card SlotB ñ External Microphone Jack E ñ USB PortC ñ Power Button F ñ KensingtonÆ Lock Slot! Headphone Jack/External Speakers ó Connect an external headphone set or speakers tothis jack. Plugging in headphones disables the built-in system speakers.