Cisco 4000 Series Integrated Services Routers - Cisco
C1-CISCO4331/K9 - Cisco 4000 Series 4331 3 x onboard WAN or LAN Ports 1000Base-T + 2 x RJ-45 Ports + 2 x SFP Ports Gigabit Ethernet 1U Rack-mountable VoIP Gateways Router
Cisco ISR4331/K9 – CSTXNetworkSupply
Cisco 4000 Family Integrated Services Router Data Sheet - Cisco
ISR4331/K9 Integrated Service Router | Free Lifetime Warranty