Xiemin Portable Charger Power Adapter for Microsoft Surface Pro 3 12 Inch Tablet with a 5v 1a USB Port (Pro 3 Charger Adapter with USB) Fits for Microsoft Surface Pro 3 12 Inch Tablet I/C Chip technology prevents your tablet's battery overcharging. Specially designed with a 5V 1A USB port for you to charge for other device while using your pro 3 tablet. Easy to carry around, on trip and travel.