Cisco 2921 Integrated Services Router - 1 x SFP (Mini-GBIC), 2 x CompactFlash (CF) Card, 4 x HWIC, 2 x Services Module, 3 x PVDM - 3 x 10/100/1000Base-T WAN - CISCO2921-SEC/K9
Hardware Installation Guide for Cisco 4000 Series Integrated Services Routers - Install and Upgrade Internal Modules and FRUs [Cisco 4000 Series Integrated Services Routers] - Cisco