45W MagSafe 2 Power Adapter The magnetic DC connector makes it easy to disconnect the cord if someone should trip over it, and also helps prevent fraying or weakening of the cables over time When securely connected, an LED lights up - an amber light lets you know that your laptop is charging, while a green light tells you that you have a full charge A clever design makes it easy to wind up and take with you Recharges the lithium-polymer battery of your MacBook Air while it's on, off or in sleep mode; it can also operate the system without a battery