Original Cisco Systems HWIC-1ADSL ADSL2/2+ WAN Interface Module Single (1x) ADSL2/2+ over PoTS WAN interface
Compatible with the following Cisco Systems Routers: 1841, 2800 series, 3800 series, 1900 2900 3900 series. For complete technical information, please visit the following URL: http://www.cisco.com/en/US/prod/collateral/routers/ps5855/product_data_sheet0900aecd80394b7e.html