Cisco PA-MC-4T1 Multi-Channel T1/PRI 4-Port Adapter Expansion Module w/Integrated CSUs/DSUs 800-02986-02 73-2691-06 A0 T98-6318-0.Cisco Model Number: PA-MC-4T1Cisco Part Number: 800-02986-02Compatible Numbers: 73-2691-06 A0 T98-6318-0