Set Side: HDMI In (3 (2.0)), Headphone Out (Phone Jack Type), RS-232C(D-Sub 9pin / Phone jack) (Phone Jack, 4pin), LG SVC only (Phone jack type) (Phone Jack Type), CI Slot (CI+ 1.4 ECP); Set Rear / Bottom: USB (2.0), RF In (2), Digital Audio Out (Optical), External Speaker Out(3.5mm phone jack), RJ45 (Usage Purpose) (LAN)