The Cisco SM-X-16G4M2X is a network module designed for Cisco Integrated Services Routers (ISR) 4000 Series. It provides additional connectivity options and expansion capabilities for the router. The module offers 16 Gigabit Ethernet ports, 4 Gigabit SFP (Small Form-Factor Pluggable) ports, and 2 10 Gigabit SFP+ ports. This allows for increased network connectivity and flexibility, enabling the router to handle higher bandwidth requirements and support a variety of network devices. The Cisco SM-X-16G4M2X module is hot-swappable, meaning it can be inserted or removed from the router without powering down the system. It is commonly used in enterprise networks to expand the capabilities of Cisco ISR 4000 Series routers and enhance network performance.