The CISCO HWIC-4ESW is a 4-port Fast Ethernet EtherSwitch interface card designed for Cisco routers like the 2800, 3800, 2900, and 3900 series. It provides LAN and WAN interface functionality, as well as port expansion capabilities. With Ethernet (RJ-45) network ports, this card allows for easy connection to various devices within a network, making it a versatile and essential component for enterprise networking setups. Designed specifically for Cisco routers, this interface card offers reliable performance and connectivity options for a range of networking needs.This card came from a working router. All works great.