The Ethernet Shield connects your Arduino device to the internet in mere minutes. Just plug this module onto your Arduino board, connect it to your network with an RJ45 cable (not included) and follow a few simple instructions to start controlling your world through the internet. The Ethernet controller of this Ethernet Shield is W5200. it is twice the buffer size of W5100 and support for up to eight simultaneous TCP/UDP connections. There is an onboard micro-SD card slot, which can be used to store files for serving over the network. Thanks to a lowered RJ45 pot, you can flexibly add most shields on top of this Ethernet Shield.