https://www.cisco.com/c/en/us/support/docs/routers/3600-series-multiservice-platforms/7261-wic-2t.html
Understanding 2-Port Serial WAN Interface Card (WIC-2T) - Cisco
The dual-serial port WAN interface cards (WICs) for the Cisco 2600 and 1700 series feature Cisco`s new, compact, high-density Smart Serial connector to support...
wan interface card2 portwic 2tunderstandingserial