CISCO NIM-ES2-4- is a 4000 series integrated service router 4-port gigabitethernet switch..
Cisco NIM-ES2-4= is a Cisco 4000 Series Integrated Services Router 4-Port Gigabit Ethernet Switch Module. The 4-port Cisco Gigabit Ethernet LAN Switch Network Interface Modules (NIMs) can reduce your company’s total cost of ownership (TCO) by integrating Gigabit Ethernet switch ports within Cisco 4000 Series Integrated Services Routers (ISRs). These low-density Gigabit Ethernet switches offer small to medium-sized businesses and enterprise branch offices a combination of switching and routing integrated into a single device
Notice that NIM-ES2-4= is the same as NIM-ES2-4.