Cisco HWIC-1DSU-T1= interface cards/adapter

HWIC-1DSU-T1=, 1-Port T1/Fractional T1 DSU/CSU WAN Interface Card Serial interfaces can be used to provide WAN access for remote sites. With support for serial speeds up to 8 Mbps per port, the 2-port serial HWIC is ideal for low- and medium-density WAN aggregation.
The HWIC-1DSU-T1 also offers an integrated CSU/DSU, simplifying configuration and management. Integration allows management of the router and CSU/DSU as a single SNMP entity while also providing detailed troubleshooting capabilities. Troubleshooting features include self-test, loopbacks, CSU/DSU reset, alarm counters, and T1 statistics.