The roof antenna is a L1/L2 35dB Gain, 50 ohm antenna. The Re-radiating amplifier has a 110V/220V Plug-in transformer which powers the amplifier and the roof antenna. The signal from the roof antenna is amplified and radiated out the Re-radiating antenna. If the receiving antenna has line of sight with the Re-radiating antenna, it will receive the signal up to 30 metert away. The antenna voltage is set at 5VDC. The customer must designate the source voltage(110/220/6-30VDC). For Example: L1/L2HNRRKIT-N/220 is a Hanger Network RRKIT with a 220V source.