Sometimes Wi-Fi is simply not an option, and you need a reliable Ethernet connection. This USB 3.0 networkadaptor and hub combo is designed for the latest MacBook Air(R) and Google Chromebook(TM) with new USB Type-C connectors. Currently the MacBook Air(R) only has one USB Type-C port which doesn't allow the use of other devices while something is plugged in. This adaptor allows you to expand up to 3 x USB 3.0 ports and provides you with an ethernet port which is non-existent on ultrabooks. Specifications: Transfer Speed: up to 80MbpsNetwork Connection: RJ45, 10/100Mbps Compatibility: Windows 10, 8.1, 8, 7, Vista, XP, 2000, Mac OS X(R) 10.5+, Linux Length : 85.0mm Width : 24.0mm Height : 17.0mm Supported USB Standards : USB 3.0 Number of USB ports : 3.0 ports Type of Hardware : Adaptor + Hub Speed of Transmission : 100.0Mb/s Number of USB ports : 3.0