Qi-infinity8482; UPGRADED Pro DC charge cable with the Original Magnetic connector for Microsoft pro3/pro4 and book -5.52.5mm DC 12V/15V 2.5-3.6A 3 feets cable for SP3/SP4 New design of high quality SP3/SP4 charge cable This upgraded design includes original magnetic connector. This wire has magnet ring to protect the DC round connector from overflow current interference DC charging cable for Microsoft Surface Pro 3, Pro 4 or Surfacebook that is compatible with our Powergrid (34200mAh), Powerplant (52,800mAh) and 35,000 mAh models only. Please note that you need to set voltage at 12V or 15V before charging your Surface Pro otherwise your device will not charge. High speed charging cable with LED light, tinned copper contacts and Electromagnetic shielding. NOTE: ONLY for 12V/15V 2.5-3.6A mobile power supply!!! No USB port or AC power supply!