Cisco EM2-HDA-4FXO - 4-port voice/fax expansion module - FXO Cisco Router Network Module Retail $249.00
Cisco EM-HDA-3FXS/4FXO - 7-port voice/fax expansion module - 3FXS/4FXO Cisco Router Network Module Retail $399.00
HP 0231A62X - MSR 4-port FXO FIC module (FIC-4FXO) - Flexible Interface Controller (FIC) analog trunk interface module with four RJ-45 phone connectors for 2/4 loops of telephone exchanges over data communications networks Retail