The Microsoft Surface USB 3.0 Gigabit Ethernet Adapter (Model 1821) is a black adapter specifically designed for Microsoft products. It features a 1:1 connection split/duplication, a USB 3.0 connector A, and an Ethernet (RJ-45) female connector B. With a cable length of 15 cm, this adapter supports gigabit Ethernet speeds and has an output voltage of 5 V. It is compatible with universal and Microsoft brands, making it a versatile and reliable option for expanding connectivity on your device.