Connecting to the MacBook’s MagSafe Power Adapter, the ChugPlug will boost an 11in MacBook Air’s battery by up to four additional hours and a 13in MacBook Air and 13in MacBook Pro’s batteries by up to three hours. The battery back measures 7.4 x 22 x 2.8cm, making it a slim portable companion for a MacBook and, weighing under 500g, no hindrance when packing a travel bag. Available at Harvey Norman, Next Byte, JR Duty Free and Dick Smith stores nationwide.