4 port modular analog PCI 3.3/5.0V card with 2 Station and 2 Trunk interfaces and HW Echo Can - Replacement for:1TDM422EF One (1) - four (4) analog ports PCI or PCI Express bus architectures Combine line (FXO) and station (FXS) modules Accepts up to four (4) single-port modules Optional DSP -based carrier grade echo cancellation module 32-bit 33MHz Loop Start or Kewl Start Signaling Temperature: 0° to 50° C Digium patented VoiceBus? technology for better audio