HWIC-2A/S= - Cisco 2-Port Asynchronous/Synchronous Serial WAN Interface Card

Expansion module - HWIC - RS-232, RS-530, X.21, V.35, RS-449, RS-530A - 2 ports - for Cisco 1841, 1841 ADSL2, 1921 4-pair, 1921 ADSL2+, 1921 T1, 19XX, 28XX, 29XX, 38XX, 39XX