The usb31000sptw usb 30 to gigabit ethernet adapter lets you add a gigabit network port to your macbook or ultrabook computer through a usb 30 port and features an integrated usb 30 pass through port that keeps your usb port available for use with other peripherals each rj45 port supports 101001000 mbps ethernet and is fully compatible with ieee 8023iuab standards an ideal replacement lan adapter or laptop accessory this compact usb 30 nic leverages the 5 gbps speed of usb 30 to pr