Audiovox XM XMAMP18 Terk 18dB In-Line Amplifier for XM6 Antenna (Black) In-line Signal Amplifier For Use With Xm6 Used In Satellite Radio Cable Runs Longer Than 100ft Connects Using F Connectors (rg6 Cable Runs) For use with Terk XM6 Home Antenna. Extends the Home Antenna RG-6 Cable an additional 100'. Ensures the strongest possible XM signal to the home receiver. One In-Line Amp must be placed every 100 feet for optimum performance. No special cable needed. Uses standard RG-6 cable.