1. Support Skype VoIP call with common telephone set; 2. Support Skype speed-dialing function; 3. Plug-and-play installation; 4. Use a single device to make/receive both; Skype and PSTN calls simultaneously 5. PC-to-PC, PC-to-PSTN, PSTN-to-PSTN calls are possible; 6. The telephone will ring when receive a call USB line and PSTN line; 7. Incoming call prompt when USB line or PSTN line is even in talk; 8. PSTN or Skype call mode able using phone key; 9. Auto-detection and auto-switch to PSTN or Skype calls; 10. PSTN phone calls continue to operate even if PC or PUPA is powered down; 11. Support DECT, 2.4G, 900M and other cordless telephone, support exchange; 12. Best quality with full-duplex and echo-free.