XINGDONGCHI US Plug Power Supply Adapter for Microsoft Windows Surface Pro 3 / Surface Pro 4 Intel i5 and i7 Core Suitable for Microsoft Surface Pro 3 / Surface Pro 4 Intel Core i5 and i7 Tablet.Not fit Intel Core M3 I/C Chip technology prevents your tablet's battery overcharging Circuit Protection : Short Circuit Protection and Overload Protection Electromagnetic immunity and high charging speed You can rest assured to use, as has been through 48 hours of aging experiments