KEYESTUDIO W5100 Ethernet Shield for Arduino Mega 2560 UNO R3 Duemilanove, Easily Connects Arduino to Internet keyestudio W5100 Ethernet Shield gives you an easy way to get your Arduino Online. It can turn your Arduino into a simple web server or use the Internet to read /write its digital and analog outputs/inputs. It is directly supported by Arduino official Ethernet Library. It also supports the read &write of mini SD card (TF card). The shield adopts stackable design. You can directly plug it to Arduino board. Its also compatible with our other shields. Adds a micro-SD card slot, can be used to store files for serving over the network