Openvox FXOS200 Dual Channel FXO FXS Module for A400 A800 A1200Model: FXOS200Retail Price: $120 FXOS200 is a Dual channel module, which builds one FXO and one FXS channel with failover capability. When PBX system is down, PSTN line connecting FXO will automatically switch to analog phone connecting with FXS. Key Benefits: Modular Design: Each FXOS200 with one FXO and one FXS channel The pin of FXOS200 is compatible with FXO 100 and FXS 100 FXOS200 is used on A400E A400P A400M A800P A1200P Simplified Asterisk PBX