The Ethernet Shield W5100 is a reliable networking module designed to add internet connectivity to Arduino boards. Powered by the Wiznet W5100 chip, it supports up to four simultaneous socket connections, enabling robust communication for IoT and web-based projects. The shield includes a built-in microSD card slot for file storage and retrieval, fully supported by the Arduino Ethernet and SD libraries. Featuring a stackable design, it integrates seamlessly with Arduino boards and other shields. With IEEE802.3af compliance, low output ripple and noise (100mVpp), and built-in overload and short-circuit protection, the W5100 ensures safe and stable operation. Perfect for building IoT devices, web servers, and network-based automation systems.